Compounds and methods for treating bacterial infections

ABSTRACT

Compounds of formula (I), pharmaceutically acceptable salts thereof, and uses of the compounds of formula (I) for treating bacterial infections are disclosed.

RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C §119(e) of U.S.Provisional Patent Application No. 61/859,910, filed Jul. 30, 2013 andU.S. Provisional Patent Application No. 61/755,537 filed on Jan. 23,2013. The contents of each of the foregoing applications are herebyincorporated by reference in their entirety.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has beensubmitted electronically in ASCII format and is hereby incorporated byreference in its entirety. Said ASCII copy, created on Jan. 6, 2014, isnamed 200070-US-NP_SL.txt and is 819 bytes in size.

BACKGROUND OF THE INVENTION

Antibiotic tolerance and resistance has become a grave threat to thesuccessful treatment of many common bacterial infections. Indeed,according to the Infectious Disease Society of America, methicillinresistant Staphylococcus aureus (MRSA) kills more Americans every yearthan emphysema, HIV/AIDS, Parkinson's disease and homicide combined. Notonly is multi-drug resistance in common infectious Gram-positive and-negative pathogens such as Enterococcus faecium, Staphylococcus aureus,Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa,Mycobacterium tuberculosis and Enterobacter species on the rise, butevidence of resistance is being seen in Salmonella and Clostridiumdifficile, and increasingly Neisseria gonorrheae (Gerard D. Wright,“Antibiotics: A New Hope,” 19 (2012) 3-10). Due to this increase inresistance, the development of new antibacterials is an importantmedical need.

SUMMARY

There remains a need for new therapies for treating bacterialinfections. The present invention provides new compounds and methods forusing the same for treating bacterial infections.

In one aspect, the invention provides a compound of formula (I), or apharmaceutically acceptable salt thereof:

wherein

X is fluorine or chlorine;

R¹ is selected from the group consisting of hydrogen, phenyl, —C≡N,tetrahydropyranyl, N-methyl-1,2,4-triazolyl, pyrimidinyl, pyridinyl,pyrazinyl, cyclopropyl, —C≡CH, CH═CH₂, and C₁-C₃ alkyl, which C₁-C₃alkyl is optionally substituted with one or more of: —OR¹⁰, halogen,—C≡N, —N₃, —SO₂CH₃, —SCH₃, —CH═CH₂, —CH═NOR¹¹ and phenyl;

R² is selected from the group consisting of hydrogen, —C≡N, pyridinyl,C₁-C₃ alkyl, which C₁-C₃ alkyl is optionally substituted with one ormore of: halogen, —OR²⁰ and —CH═NOR²¹;

R³ is hydrogen or C₁-C₃ alkyl;

R¹⁰ is for each occurrence independently selected from the groupconsisting of hydrogen, C₁-C₄ alkyl and (CH₂)₂OCH₃; and

R¹¹, R²⁰ and R²¹ are for each occurrence independently hydrogen or C₁-C₄alkyl.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, and a pharmaceutically acceptable excipient or diluent.

In one aspect, the invention provides a method for treating a bacterialinfection in a subject in need thereof comprising administering aneffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt thereof, to the subject.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treating abacterial infection.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating a bacterial infection.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating a bacterial infection.

In one aspect, the invention provides a method for inhibiting bacterialDNA gyrase in a subject in need thereof, comprising administering aneffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for inhibitingbacterial DNA gyrase.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for inhibiting bacterial DNA gyrase.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for inhibiting bacterial DNA gyrase.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph illustrating the efficacy of Example 5 in a thighlesion model induced by S. aureus USA100 in neutropenic CD1 mice.

FIG. 2 is a graph illustrating the efficacy of Example 5 in a thighlesion model induced by S. pyogenes ATCC12384 in neutropenic mice.

DETAILED DESCRIPTION OF THE INVENTION Compounds

The present invention provides, at least in part, to compounds, andpharmaceutically acceptable salts thereof, of formula (I):

wherein

X is fluorine or chlorine;

R¹ is selected from the group consisting of hydrogen, phenyl, —C≡N,tetrahydropyranyl, N-methyl-1,2,4-triazolyl, pyrimidinyl, pyridinyl,pyrazinyl, cyclopropyl, —C≡CH, CH═CH₂, and C₁-C₃ alkyl, which C₁-C₃alkyl is optionally substituted with one or more of: —OR¹⁰, halogen,—C≡N, —N₃, —SO₂CH₃, —SCH₃, —CH═CH₂, —CH═NOR¹¹ and phenyl;

R² is selected from the group consisting of hydrogen, —C≡N, pyridinyl,C₁-C₃ alkyl, which C₁-C₃ alkyl is optionally substituted with one ormore of: halogen, —OR²⁰ and —CH═NOR²¹;

R³ is hydrogen or C₁-C₃ alkyl;

R¹⁰ is for each occurrence independently selected from the groupconsisting of hydrogen, C₁-C₄ alkyl and —(CH₂)₂OCH₃; and

R¹¹, R²⁰ and R²¹ are for each occurrence independently hydrogen or C₁-C₄alkyl.

In one aspect, R¹ is hydrogen, methyl, ethyl, phenyl, —CH₂-phenyl,—CH₂F, —CH₂OCH₃, —CH₂CH═CH₂, tetrahydropyranyl, —(CH₂)₃OH, —(CH₂)₃F,—(CH₂)₃OH, —(CH₂)₃F, —CH═CH₂, —C≡N, —CH═NOCH₃, —CH₂SCH₃, —CH₂SO₂CH₃,—CH₂N₃, —CH₂OCH₂CH₃, —CH₂O(CH₂)₂OCH₃, cyclopropyl, pyridinyl,—CH(CH₃)OCH₃, pyrimidinyl, pyrazinyl, —C≡CH, N-methyl-1,2,4-triazolyl,—CH(OH)CH₃, —CH═NOH or —CH₂OH.

In one aspect, R² is hydrogen, methyl, ethyl, —CH₂F, —CH₂OCH₃, —CH₂OH,—CH═NOH, —CH₂N₃, pyridinyl, —C≡N or —CH═NHOCH₃.

In one aspect, R³ is hydrogen or methyl.

In one aspect, R¹⁰ is hydrogen, methyl, ethyl or —(CH₂)₂OCH₃.

In one aspect, R¹¹ is hydrogen or methyl.

In one aspect, R²⁰ is hydrogen, methyl or ethyl.

In one aspect R²¹ is hydrogen or methyl.

In one aspect, in the compound of formula (I), X is fluorine and R¹, R²and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ ismethyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is methyl.

In one aspect, in the compound of formula (I), X is fluorine, R¹ isethyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ isphenyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂-phenyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ ishydrogen and R² and R³ are each methyl.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is ethyl.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂F and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂OCH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is —CH₂F.

In one aspect, in the compound of formula (I), X is chlorine, R¹ and R³are each hydrogen and R² is —CH₂OCH₃.

In one aspect, in the compound of formula (I), X is chlorine, R¹ and R³are each hydrogen and R² is methyl.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R²are each methyl and R³ is hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂CH═CH₂ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is —CH₂OH.

In one aspect, in the compound of formula (I), X is fluorine, R¹ istetrahydropyranyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—(CH₂)₃OH and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—(CH₂)₃F and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is chlorine, R¹ and R³are each hydrogen and R² is —CH₂F.

In one aspect, in the compound of formula (I), X is chlorine, R¹ is—(CH₂)₃OH and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is chlorine, R¹ is—(CH₂)₃F and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is —CH₂OCH₃.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH═CH₂ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is —CH═NOH.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is —C≡Nand R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH═NOCH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is —CH═NHOCH₃.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is —CH₂N₃.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂SCH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂SO₂CH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂N₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂OCH₂CH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂O(CH₂)₂OCH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CHF₂ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ iscyclopropyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is pyridinyl.

In one aspect, in the compound of formula (I), X is fluorine, R¹ ispyridinyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH(CH₃)OCH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ ispyrimidinyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ ispyrazinyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—C≡CH and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is chlorine, R¹ ismethyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ isN-methyl-1,2,4-triazolyl and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH(OH)CH₃ and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH(OH)CH₂OH and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH═NOH and R² and R³ are each hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ and R³are each hydrogen and R² is —C≡N.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂OCH₃, R² is methyl and R³ is hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂F, R² is methyl and R³ is hydrogen.

In one aspect, in the compound of formula (I), X is fluorine, R¹ is—CH₂OH and R² and R³ are each hydrogen.

In some embodiments, the compound of formula (I) has the structure offormula (Ia), or a pharmaceutically acceptable salt thereof:

wherein

R^(1a) is hydrogen or C₁-C₃ alkyl, which C₁-C₃ alkyl is optionallysubstituted with halogen or OR^(11a);

R^(2a) is hydrogen or C₁-C₃ alkyl, which C₁-C₃ alkyl is optionallysubstituted with halogen or OR^(21a); and

R^(11a) and R^(21a) are for each occurrence independently hydrogen orC₁-C₄ alkyl.

In one aspect, R^(1a) is hydrogen, —(CH₂)₃OH, —(CH₂)₃F or methyl.

In one aspect, R^(2a) is —CH₂OCH₃, methyl, —CH₂F or hydrogen.

In one aspect, R^(11a) is hydrogen or methyl.

In one aspect, R^(21a) is hydrogen or methyl

In one aspect, in the compound of formula (Ia), R^(1a) is hydrogen andR^(2a) is —CH₂OCH₃.

In one aspect, in the compound of formula (Ia), R^(1a) is hydrogen andR^(2a) is methyl.

In one aspect, in the compound of formula (Ia), R^(1a) is hydrogen andR^(2a) is —CH₂F.

In one aspect, in the compound of formula (Ia), R^(1a) is —(CH₂)₃OH andR^(2a) is hydrogen.

In one aspect, in the compound of formula (Ia), R^(1a) is —(CH₂)₃F andR^(2a) and is hydrogen.

In one aspect, in the compound of formula (Ia), R^(1a) is methyl andR^(2a) is hydrogen.

In some embodiments, the compound of formula (I) has the structure offormula (Ib):

wherein

R^(1b) is selected from the group consisting of hydrogen, phenyl, —C≡N,tetrahydropyranyl, 1,2,4-triazolyl, pyrimidinyl, pyridinyl, pyrazinyl,cyclopropyl, —C≡CH, —CH═CH₂ and C₁-C₃ alkyl, which C₁-C₃ alkyl isoptionally substituted with one or more of: OR^(10b), halogen, —C≡N,—N₃, —SO₂CH₃, —SCH₃, —CH═CH₂, —CH═NOR^(11b) and phenyl;

R^(2b) is selected from the group consisting of hydrogen, —C≡N, C₁-C₃alkyl, which C₁-C₃ alkyl is optionally substituted with one or more of:halogen, OR^(20b) and CH═NOR^(21b);

R^(3b) is hydrogen or C₁-C₄ alkyl;

R^(10b) is for each occurrence independently selected from the groupconsisting of hydrogen, C₁-C₄ alkyl and —(CH₂)₂OCH₃; and

R^(11b), R^(20b) and R^(21b) are for each occurrence independentlyhydrogen or C₁-C₄ alkyl.

In one aspect, R^(1b) is hydrogen, methyl, ethyl, phenyl, —CH₂-phenyl,—CH₂F, —CH₂OCH₃, —CH₂CH═CH₂, tetrahydropyranyl, —(CH₂)₃OH, —(CH₂)₃F,—(CH₂)₃OH, —(CH₂)₃F, —CH═CH₂, —C≡N, —CH═NOCH₃, —CH₂SCH₃, —CH₂SO₂CH₃,—CH₂N₃, —CH₂OCH₂CH₃, —CH₂O(CH₂)₂OCH₃, cyclopropyl, pyridinyl,—CH(CH₃)OCH₃, pyrimidinyl, pyrazinyl, —C≡CH, N-methyl-1,2,4-triazolyl,—CH(OH)CH₃, —CH═NOH or —CH₂OH.

In one aspect, R^(2b) is hydrogen, methyl, ethyl, —CH₂F, —CH₂OH,—CH═NOH, —CH₂N₃, pyridinyl, —C≡N or —CH═NHOCH₃.

In one aspect, R^(3b) is hydrogen or methyl.

In one aspect, R^(10b) is hydrogen, methyl, ethyl or —(CH₂)₂OCH₃.

In one aspect, R^(11b) is hydrogen or methyl.

In one aspect, R^(20b) is hydrogen, methyl or ethyl.

In one aspect R^(21b) is hydrogen or methyl.

In one aspect, in the compound of formula (Ib), R^(1b) is methyl andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is methyl.

In one aspect, in the compound of formula (Ib), R^(1b) is ethyl andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is phenyl andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂-phenyland R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is hydrogen andR^(2b) and R^(3b) are each methyl.

In one aspect, in the compound of formula (Ib), Rb and R^(3b) are eachhydrogen and R^(2b) is ethyl.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂F andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂OCH₃ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is —CH₂F.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(2b) areeach methyl and R^(3b) is hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂CH═CH₂ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is —CH₂OH.

In one aspect, in the compound of formula (Ib), R^(1b) istetrahydropyranyl and R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —(CH₂)₃OH andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —(CH₂)₃F andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is —CH₂OCH₃.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH═CH₂ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is —CH═NOH.

In one aspect, in the compound of formula (Ib), R^(1b) is —C≡N andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH═NOCH₃ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is —CH═NHOCH₃.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is —CH₂N₃.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂SCH₃ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂SO₂CH₃ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂N₃ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂OCH₂CH₃and R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is—CH₂O(CH₂)₂OCH₃ and R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CHF₂ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is cyclopropyland R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (I), R^(1b) and R^(3b) areeach hydrogen and R^(2b) is pyridinyl.

In one aspect, in the compound of formula (I), R^(1b) is pyridinyl andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH(CH₃)OCH₃and R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is pyrimidinyland R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is pyrazinyl andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —C≡CH andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) isN-methyl-1,2,4-triazolyl and R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH(OH)CH₃ andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH(OH)CH₂OHand R^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH═NOH andR^(2b) and R^(3b) are each hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) and R^(3b) areeach hydrogen and R^(3b) is —C≡N.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂OCH₃,R^(2b) is methyl and R^(3b) is hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂F, R^(2b)is methyl and R^(3b) is hydrogen.

In one aspect, in the compound of formula (Ib), R^(1b) is —CH₂OH andR^(2b) and R^(3b) are each hydrogen.

In some embodiments, the compound of formula (I) has the structure offormula (Ic), or a pharmaceutically acceptable salt thereof:

wherein

R^(1c) is phenyl, N-methyl-1,2,4-triazolyl, tetrahydropyranyl,pyrimidinyl, pyridinyl, pyrazinyl or C₁-C₃ alkyl, C₁-C₃ alkyl is whichoptionally substituted with one or more of: phenyl, halogen, —N₃ orOR^(10c); and

R^(10c) is for each occurrence hydrogen or C₁-C₄ alkyl.

In one aspect, R^(1c) is methyl, ethyl, phenyl, —CH₂-phenyl, —CH₂F,—CH₂OCH₃, tetrahydropyranyl, —CH₂N₃, pyridinyl, pyrimidinyl, pyrazinyl,—CH(CH₃)OCH₃, N-methyl-1,2,4-triazolyl or —CH₂OH.

In one aspect, R^(10c) is hydrogen or methyl.

In one aspect, in the compound of formula (Ic), R^(1c) is methyl.

In one aspect, in the compound of formula (Ic), R^(1c) is ethyl.

In one aspect, in the compound of formula (Ic), R^(1c) is phenyl.

In one aspect, in the compound of formula (Ic), R^(1c) is —CH₂-phenyl.

In one aspect, in the compound of formula (Ic), R^(1c) is —CH₂F.

In one aspect, in the compound of formula (Ic), R^(1c) is —CH₂OCH₃.

In one aspect, in the compound of formula (Ic), R^(1c) istetrahydropyranyl.

In one aspect, in the compound of formula (Ic), R^(1c) is —CH₂N₃.

In one aspect, in the compound of formula (Ic), R^(1c) is pyridinyl.

In one aspect, in the compound of formula (Ic), R^(1c) is pyrimidinyl.

In one aspect, in the compound of formula (Ic), R^(1c) is pyrazinyl.

In one aspect, in the compound of formula (Ic), R^(1c) is —CH(CH₃)OCH₃.

In one aspect, in the compound of formula (Ic), R^(1c) isN-methyl-1,2,4-triazolyl.

In one aspect, in the compound of formula (Ic), R^(1c) is —CH₂OH.

In some embodiments, the compound of formula (I) has the structure offormula (Id), or a pharmaceutically acceptable salt thereof:

wherein

X is chlorine or fluorine;

R^(1d) is selected from the group consisting of hydrogen, phenyl, —C≡N,tetrahydropyranyl, N-methyl-1,2,4-triazolyl, pyrimidinyl, pyridinyl,pyrazinyl, cyclopropyl, —C≡CH, —CH═CH₂, and C₁-C₃ alkyl, which C₁-C₃alkyl is optionally substituted with one or more of: —OR^(10d), halogen,—C≡N, —N₃, —SO₂CH₃, —SCH₃, —CH═CH₂, —CH═NOR^(11d) and phenyl;

R^(10d) is for each occurrence independently selected from the groupconsisting of hydrogen, C₁-C₄ alkyl and —(CH₂)₂OCH₃; and

R^(11d) is for each occurrence independently hydrogen or C₁-C₄ alkyl.

In one aspect, R^(1d) is methyl, ethyl, phenyl, —CH₂-phenyl, —CH₂F,—CH₂OCH₃, —CH₂CH═CH₂, tetrahydropyranyl, —(CH₂)₃OH, —(CH₂)₃F, —CH═CH₂,—C≡N, —CH═NOCH₃, —CH₂SCH₃, —CH₂SO₂CH₃, —CH₂N₃, —CH₂OCH₂CH₃,—CH₂O(CH₂)₂OCH₃, pyridinyl, —CH(CH₃)OCH₃, pyrimidinyl, pyrazinyl, —C≡CH,N-methyl-1,2,4-triazolyl, —CH(OH)CH₃, —CH(OH)CH₂OH or —CH═NOH.

In one aspect, R^(10d) is hydrogen, methyl or ethyl.

In one aspect, R^(10d) is hydrogen or methyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is methyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is ethyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is phenyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂-phenyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂F.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂OCH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂CH═CH₂.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is tetrahydropyranyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —(CH₂)₂OH.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —(CH₂)₂F.

In one aspect, in the compound of formula (Id), X is chlorine and R^(1d)is —(CH₂)₃OH.

In one aspect, in the compound of formula (Id), X is chlorine and R^(1d)is —(CH₂)₃F.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —(CH₂)₃OH.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH═CH₂.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —(CH₂)₃OH.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —C≡N.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH═NOCH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂SCH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂SO₂CH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂N₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂OCH₂CH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH₂O(CH₂)₂OCH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CHF₂.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is pyridinyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH(CH₃)OCH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is pyrimidinyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is pyrazinyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —C≡CH.

In one aspect, in the compound of formula (Id), X is chlorine and R^(1d)is methyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is N-methyl-1,2,4-triazolyl.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH(OH)CH₃.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH(OH)CH₂OH.

In one aspect, in the compound of formula (Id), X is fluorine and R^(1d)is —CH═NOH.

In some embodiments, the compound of formula (I) has the structure offormula (Ie) or a pharmaceutically acceptable salt thereof:

wherein

X is chlorine or fluorine;

R^(2e) is selected from the group consisting of pyridinyl, —C≡N or C₁-C₃alkyl, which C₁-C₃ alkyl is optionally substituted with one or more of:OR^(20e), halogen, azido and CH═NOR^(21e); and

R^(20e) and R^(21e) are for each occurrence independently hydrogen orC₁-C₄ alkyl.

In one aspect, R^(2e) is methyl, ethyl, —CH₂OCH₃, —CH₂OH, —CH₂F, —CH₂N₃,pyridinyl, —CH═NOH or —CH═NOCH₃.

In one aspect R^(20e) is hydrogen or methyl.

In one aspect, R^(21e) is hydrogen or methyl.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is methyl.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is ethyl.

In one aspect, in the compound of formula (Ie), X is chlorine and R^(2e)is —CH₂OCH₃.

In one aspect, in the compound of formula (Ie), X is chlorine and R^(2e)is methyl.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is —CH₂OCH₃.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is —CH₂OH.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is —CH₂F.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is —CH₂N₃.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is pyridinyl.

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is —CH═NOH

In one aspect, in the compound of formula (Ie), X is fluorine and R^(2e)is —CH═NOCH₃.

In some embodiments, the compound of formula (I) has the structure offormula (If) or a pharmaceutically acceptable salt thereof:

wherein

X is chlorine or fluorine;

R^(2f) is pyridinyl or C₁-C₃ alkyl, which C₁-C₃ alkyl is optionallysubstituted with one or more halogen or —OR^(20f); and

R^(20f) is for each occurrence independently hydrogen or C₁-C₄ alkyl.

In one aspect, R^(2f) is methyl, ethyl, —CH₂F, —CH₂OCH₃ or —CH₂OH.

In one aspect, R^(20f) is hydrogen or methyl.

In one aspect, in the compound of formula (If), X is fluorine and R^(2f)is methyl.

In one aspect, in the compound of formula (If), X is fluorine and R^(2f)is ethyl.

In one aspect, in the compound of formula (If), X is fluorine and R^(2f)is —CH₂F.

In one aspect, in the compound of formula (If), X is chlorine and R^(2f)is —CH₂OCH₃.

In one aspect, in the compound of formula (If), X is chlorine and R^(2f)is methyl.

In one aspect, in the compound of formula (If), X is fluorine and R^(2f)is —CH₂OH.

In one aspect, in the compound of formula (If), X is chlorine and R^(2f)is —CH₂F.

In one aspect, in the compound of formula (If), X is fluorine and R^(2f)is —CH₂OCH₃.

In some embodiments, the compound of formula (I) has the structure offormula (Ig) or a pharmaceutically acceptable salt thereof:

wherein

R^(1g) is C₁-C₃ alkyl optionally substituted by one or more of halogenand OR^(10g);

R^(2g) is C₁-C₃ alkyl; and

R^(10g) is for each occurrence independently hydrogen or C₁-C₄ alkyl.

In one aspect, R^(1g) is methyl, —CH₂OCH₃ or —CH₂F.

In one aspect, R^(2g) is methyl.

In one aspect, R^(10g) is hydrogen or methyl.

In one aspect, in the compound of formula (Ig), X is fluorine, R^(1g)and R^(2d) are each methyl.

In one aspect, in the compound of formula (Ig), X is fluorine, R^(1g) is—CH₂OCH₃ and R^(2d) is methyl.

In one aspect, in the compound of formula (Ig), X is fluorine, R^(1g) is—CH₂F and R^(2d) is methyl.

In one aspect, the present invention provides, at least in part, to thefollowing compounds, or a pharmaceutically acceptable salt, thereof:

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-(2-oxo-1,3-oxazolidin-3-yl)-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5S)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5R)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-[(4S)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-[(4R)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione)

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-[(4R)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-[(4S)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-(5,5-Dimethyl-2-oxo-1,3-oxazolidin-3-yl)-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-[(5S)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-[(5R)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Chloro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Chloro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

((2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((R)-5-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((4S,5R)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((4R,5S)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((S)-4-Allyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-((S)-5-(hydroxymethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

((2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-[(4S-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-hydroxypropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo]4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-((S)-4-(2-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Chloro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Choro-8-((S)-4-(3-hydroxpropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Choro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(hydroxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-2-oxo-4-vinyloxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-4-carbonitrile

(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-[(5R)-5-(Azidomethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylthio)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]- 2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylsulfonyl)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]- 2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((R)-4-(Azidomethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((S)-4-(azidomethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-[(4S)-4-(Ethoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(2-methoxyethoxy)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-8-((R)-4-(Difluoromethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((S)-4-Cyclopropyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)trione

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)trione

(2R,4S,4aS)-11-Fluoro-8-((R)-4-((R)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((S)-4-Ethynyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((S)-4-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]- 2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]- 2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)trione

{(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidin-4-yl}acetonitrile

(2R,4S,4aS)-8-((R)-4-((R)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]- 2′,4′,6′(3′H)-trione

(2R,4S,4aS)-8-((R)-4-((S)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]- 2′,4′,6′(3′H)-trione

(2R,4S,4aS)-11-fluoro-8-{(4S)-4-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

(5R)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrile

(5S)-3-[(2R,4S,4aS)-11-fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrile

In one aspect, the invention pertains to a product obtainable by anyprocess described in the Exemplification of the Invention.

The term “alkyl” includes straight and branched chain saturatedhydrocarbon radicals having the specified number of carbon atoms. Forexample, “C₁-C₃ alkyl” includes alkyl groups with 1-3 carbon atoms, forexample, methyl, ethyl, n-propyl and isopropyl groups. Likewise, thelanguage “C₁-C₄ alkyl” includes alkyl groups with 1-4 carbon atoms, forexample methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl andtert-butyl groups.

The term “halogen” includes chlorine, fluorine, bromine and iodine.

The term “tetrahydropyranyl” includes

The term “N-methyl-1,2,4-triazolyl” includes

The term “pyridinyl” includes

The term “pyrimidinyl” includes

The term “pyrazinyl” includes

The language “pharmaceutically acceptable salt” includes acid additionor base salts that retain the biological effectiveness and properties ofthe compounds of this invention and, which typically are notbiologically or otherwise undesirable. In many cases, the compounds ofthe present invention are capable of forming acid and/or base salts byvirtue of the presence of amino and/or carboxyl groups or groups similarthereto.

Pharmaceutically acceptable acid addition salts can be formed withinorganic acids and organic acids, e.g., acetate, aspartate, benzoate,besylate, bromide/hydrobromide, bicarbonate/carbonate,bisulfate/sulfate, camphorsulfonate, chloride/hydrochloride,chlortheophyllonate, citrate, ethandisulfonate, fumarate, gluceptate,gluconate, glucuronate, hippurate, hydroiodide/iodide, isethionate,lactate, lactobionate, laurylsulfate, malate, maleate, malonate,mandelate, mesylate, methylsulphate, naphthoate, napsylate, nicotinate,nitrate, octadecanoate, oleate, oxalate, palmitate, palmoate,phosphate/hydrogen phosphate/dihydrogen phosphate, polygalacturonate,propionate, stearate, succinate, subsalicylate, tartrate, tosylate andtrifluoroacetate salts. Inorganic acids from which salts can be derivedinclude, for example, hydrochloric acid, hydrobromic acid, sulfuricacid, nitric acid, phosphoric acid, and the like. Organic acids fromwhich salts can be derived include, for example, acetic acid, propionicacid, glycolic acid, oxalic acid, maleic acid, malonic acid, succinicacid, fumaric acid, tartaric acid, citric acid, benzoic acid, mandelicacid, methanesulfonic acid, ethanesulfonic acid, toluenesulfonic acid,trifluoroacetic acid, sulfosalicylic acid, and the like.Pharmaceutically acceptable base addition salts can be formed withinorganic and organic bases.

Inorganic bases from which salts can be derived include, for example,ammonium salts and metals from columns I to XII of the periodic table.In certain embodiments, the salts are derived from sodium, potassium,ammonium, calcium, magnesium, iron, silver, zinc, and copper;particularly suitable salts include ammonium, potassium, sodium, calciumand magnesium salts. Organic bases from which salts can be derivedinclude, for example, primary, secondary, and tertiary amines,substituted amines including naturally occurring substituted amines,cyclic amines, basic ion exchange resins, and the like. Certain organicamines include isopropylamine, benzathine, cholinate, diethanolamine,diethylamine, lysine, meglumine, piperazine and tromethamine.

The pharmaceutically acceptable salts of the present invention can besynthesized from a basic or acidic moiety, by conventional chemicalmethods. Generally, such salts can be prepared by reacting free acidforms of these compounds with a stoichiometric amount of the appropriatebase (such as Na⁺, Ca²⁺, Mg²⁺, or K⁺ hydroxide, carbonate, bicarbonateor the like), or by reacting free base forms of these compounds with astoichiometric amount of the appropriate acid. Such reactions aretypically carried out in water or in an organic solvent, or in a mixtureof the two. Generally, use of non-aqueous media like ether, ethylacetate, ethanol, isopropanol, or acetonitrile is desirable, wherepracticable. Lists of additional suitable salts can be found, e.g., in“Remington's Pharmaceutical Sciences,” 20th ed., Mack PublishingCompany, Easton, Pa., (1985); and in “Handbook of Pharmaceutical Salts:Properties, Selection, and Use” by Stahl and Wermuth (Wiley-VCH,Weinheim, Germany, 2002).

Any formula given herein is also intended to represent unlabeled formsas well as isotopically labeled forms for the compound of formula (I).Isotopically labeled compounds have structures depicted by the formulasgiven herein except that one or more atoms are replaced by an atomhaving a selected atomic mass or mass number. Examples of isotopes thatcan be incorporated into the compound of formula (I) include isotopes ofhydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine and chlorine,such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁶F, ³¹P, ³²P, ³⁵S, ³⁶Cl and ¹²⁵I.The invention includes various isotopically labeled compounds of formula(I) into which radioactive isotopes, such as ²H, ³H, ¹³C and ¹⁴C, arepresent. Isotopically labeled compounds of formula (I) can generally beprepared by convention techniques known to those skilled in the art orby processes analogous to those described in the accompanying Examplesusing appropriate isotopically labeled reagents in place of thenon-labeled reagents previously employed.

The compounds of formula (I) may have different isomeric forms. Thelanguage “optical isomer” or “stereoisomer” refers to any of the variousstereoisomeric configurations which may exist for a given compound ofthe present invention. It is understood that a substituent may beattached at a chiral center of a carbon atom and, therefore, theinvention includes enantiomers, diastereomers and racemates of thecompound. The term “enantiomer” includes pairs of stereoisomers that arenon-superimposable mirror images of each other. A 1:1 mixture of a pairof enantiomers is a racemic mixture. The term is used to designate aracemic mixture where appropriate. The terms “diastereomers” or“diastereoisomers” include stereoisomers that have at least twoasymmetric atoms, but which are not mirror images of each other. Theabsolute stereochemistry is specified according to theCahn-Ingold-Prelog R-S system. When a compound is a pure enantiomer, thestereochemistry at each chiral center may be specified by either R or S.Resolved compounds whose absolute configuration is unknown can bedesignated (+) or (−) depending on the direction (dextro- orlevorotatory) which they rotate plane polarized light at the wavelengthof the sodium D line. Certain of the compounds described herein containone or more asymmetric centers or axes and may thus give rise toenantiomers, diastereomers or other stereoisomeric forms that may bedefined, in terms of absolute stereochemistry, as (R)- or (S)-. Thepresent invention is meant to include all such possible isomers,including racemic mixtures, optically pure forms and intermediatemixtures. Optically active (R)- and (S)-isomers may be prepared usingchiral synthons or chiral reagents, or resolved using conventionaltechniques well known in the art, such as chiral HPLC.

Pharmaceutical Compositions

In some embodiments, the invention provides a pharmaceutical compositioncomprising a compound of formula (I) and a pharmaceutically acceptableexcipient or diluent.

The language “pharmaceutically acceptable excipient or diluent” includescompounds, materials, compositions, and/or dosage forms which are,within the scope of sound medical judgment, suitable for use in contactwith the tissues of human beings and animals without excessive toxicity,irritation, allergic response, or other problem or complication,commensurate with a reasonable benefit/risk ratio.

The compositions of the invention may be in a form suitable for oral use(for example as tablets, lozenges, hard or soft capsules, aqueous oroily suspensions, emulsions, dispersible powders or granules, syrups orelixirs), for topical use (for example as creams, ointments, gels, oraqueous or oily solutions or suspensions), for administration byinhalation (for example as a finely divided powder or a liquid aerosol),for administration by insufflation (for example as a finely dividedpowder), for parenteral administration (for example, as a sterileaqueous or oily solution for intravenous, subcutaneous, intramuscular orintramuscular dosing or as a suppository for rectal dosing) or forintraocular administration. The compositions of the invention may beobtained by conventional procedures using conventional pharmaceuticalexcipients well known in the art. Thus, compositions intended for oraluse may contain, for example, one or more coloring, sweetening,flavoring and/or preservative agents.

Suitable pharmaceutically acceptable excipients for a tablet formulationinclude, for example, inert diluents such as lactose, sodium carbonate,calcium phosphate or calcium carbonate; granulating and disintegratingagents such as corn starch or algenic acid; binding agents such asstarch; lubricating agents such as magnesium stearate, stearic acid ortalc; preservative agents such as ethyl or propyl p-hydroxybenzoate; andanti-oxidants, such as ascorbic acid. Tablet formulations may beuncoated or coated either to modify their disintegration and thesubsequent absorption of the active ingredient within thegastrointestinal tract, or to improve their stability and/or appearance,in either case, using conventional coating agents and procedures wellknown in the art.

Compositions for oral use may be in the form of hard gelatin capsules inwhich the active ingredient is mixed with an inert solid diluent, forexample, calcium carbonate, calcium phosphate or kaolin, or as softgelatin capsules in which the active ingredient is mixed with water oran oil such as peanut oil, liquid paraffin, or olive oil.

Aqueous suspensions generally contain the active ingredient in finelypowdered form or in the form of nano or micronized particles togetherwith one or more suspending agents, such as sodiumcarboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose,sodium alginate, polyvinyl-pyrrolidone, gum tragacanth and gum acacia;dispersing or wetting agents such as lecithin or condensation productsof an alkylene oxide with fatty acids (for example polyoxethylenestearate), or condensation products of ethylene oxide with long chainaliphatic alcohols, for example heptadecaethyleneoxycetanol, orcondensation products of ethylene oxide with partial esters derived fromfatty acids and a hexitol such as polyoxyethylene sorbitol monooleate,or condensation products of ethylene oxide with long chain aliphaticalcohols, for example heptadecaethyleneoxycetanol, or condensationproducts of ethylene oxide with partial esters derived from fatty acidsand a hexitol such as polyoxyethylene sorbitol monooleate, orcondensation products of ethylene oxide with partial esters derived fromfatty acids and hexitol anhydrides, for example polyethylene sorbitanmonooleate. The aqueous suspensions may also contain one or morepreservatives such as ethyl or propyl p-hydroxybenzoate; anti-oxidantssuch as ascorbic acid); coloring agents; flavoring agents; and/orsweetening agents such as sucrose, saccharine or aspartame.

Oily suspensions may be formulated by suspending the active ingredientin a vegetable oil such as arachis oil, olive oil, sesame oil or coconutoil or in a mineral oil such as liquid paraffin. The oily suspensionsmay also contain a thickening agent such as beeswax, hard paraffin orcetyl alcohol. Sweetening agents such as those set out above, andflavoring agents may be added to provide a palatable oral preparation.These compositions may be preserved by the addition of an anti-oxidantsuch as ascorbic acid.

Dispersible powders and granules suitable for preparation of an aqueoussuspension by the addition of water generally contain the activeingredient together with a dispersing or wetting agent, suspending agentand one or more preservatives. Suitable dispersing or wetting agents andsuspending agents are exemplified by those already mentioned above.Additional excipients such as sweetening, flavoring and coloring agents,may also be present.

The pharmaceutical compositions of the invention may also be in the formof oil-in-water emulsions. The oily phase may be a vegetable oil, suchas olive oil or arachis oil, or a mineral oil, such as for exampleliquid paraffin or a mixture of any of these. Suitable emulsifyingagents may be, for example, naturally-occurring gums such as gum acaciaor gum tragacanth, naturally-occurring phosphatides such as soya bean,lecithin, an esters or partial esters derived from fatty acids andhexitol anhydrides (for example sorbitan monooleate) and condensationproducts of the said partial esters with ethylene oxide such aspolyoxyethylene sorbitan monooleate. The emulsions may also containsweetening, flavoring and preservative agents.

Syrups and elixirs may be formulated with sweetening agents such asglycerol, propylene glycol, sorbitol, aspartame or sucrose, and may alsocontain a demulcent, preservative, flavoring and/or coloring agent.

The pharmaceutical compositions may also be in the form of a sterileinjectable aqueous or oily suspension, which may be formulated accordingto known procedures using one or more of the appropriate dispersing orwetting agents and suspending agents, which have been mentioned above. Asterile injectable preparation may also be a sterile injectable solutionor suspension in a non-toxic parenterally-acceptable diluent or solvent,for example a solution in 1,3-butanediol.

Compositions for administration by inhalation may be in the form of aconventional pressurized aerosol arranged to dispense the activeingredient either as an aerosol containing finely divided solid orliquid droplets. Conventional aerosol propellants such as volatilefluorinated hydrocarbons or hydrocarbons may be used and the aerosoldevice is conveniently arranged to dispense a metered quantity of activeingredient. For further information on formulation the reader isreferred to Chapter 25.2 in Volume 5 of Comprehensive MedicinalChemistry (Corwin Hansch; Chairman of Editorial Board), Pergamon Press1990.

The amount of active ingredient that is combined with one or moreexcipients to produce a single dosage form will necessarily varydepending upon the host treated and the particular route ofadministration. For further information on Routes of Administration andDosage Regimes the reader is referred to Chapter 25.3 in Volume 5 ofComprehensive Medicinal Chemistry (Corwin Hansch; Chairman of EditorialBoard), Pergamon Press 1990.

In some embodiments, the total amount of a compound of formula (I)administered to a subject may be between 400 mg to 10 g, between 400mg-4 g, between 400-4000 mg, between 400-2000 mg, between 500-1900 mg,between 600-1800 mg, between 700-1700 mg or between 800-1600 mg, forexample, 800 mg, 825 mg, 875 mg, 900 mg, 925 mg, 950 mg, 975 mg, 1000mg, 1025 mg, 1050 mg, 1075 mg, 1100 mg, 1125 mg, 1150 mg, 1175 mg, 1200mg, 1225 mg, 1250 mg, 1275 mg, 1300 mg, 1325 mg, 1350 mg, 1375 mg, 1400mg, 1425 mg, 1450 mg, 1475 mg, 1500 mg, 1525 mg, 1550 mg, 1575 mg or1600 mg. In some embodiments, the total amount of a compound of formula(I) administered to a subject may be between 400-500 mg, 500-600 mg,600-700 mg, 700-800 mg, 800-900 mg, 900-1000 mg, 1000-1100 mg, 1100-1200mg, 1200-1300 mg, 1300-1400 mg, 1400-1500 mg, 1500-1600 mg, 1600-1700mg, 1700-1800 mg, 1800-1900 mg or 1900-2000 mg.

The compound of formula (I) may be administered once, twice, three timesa day or as many times in a 24 hour period as medically necessary. Oneof skill in the art would readily be able to determine the amount ofeach individual dose based on the subject. In some embodiments, thecompound of formula (I) is administered in one dosage form. In someembodiments, the compound of formula (I) is administered in multipledosage forms.

Methods of Use

In one aspect, the invention provides a method for treating a bacterialinfection in a subject in need thereof comprising administering aneffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treating abacterial infection.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating a bacterial infection.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating a bacterial infection.

The language “bacterial infection” includes infections caused by one ormore species of Gram-negative, Gram-positive, or atypical bacteria.

In some embodiments, the bacterial infection is caused by Gram-positivebacteria, such as Staphylococcus aureus, Streptococcus pyogenes,Streptococcus pneumoniae, Streptococcus agalactiae, Bacillus anthracis,Bacillus cereus and Bacillus subtilis.

In some embodiments, the infection is caused by Gram-negative bacteria,such as Haemophilus influenzae, Acinetobacter baumannii, Citrobacterfreundii, Escherichia coli, Enterobacter cloacae, Pseudomonasaeruginosa, Klebsiella pneumoniae, and Neisseria gonorrhoeae.

In some embodiments, the infection is caused by Mycobacteriaceae, suchas Mycobacterium tuberculosis, Mycobacterium avium-intracellulare,Mycobacterium marinum, Mycobacterium ulcerans and Mycobacteriumkansasii.

In some embodiments, the infection is caused by atypical bacteria, suchas Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionellapneumophila.

In some embodiments, the bacteria are resistant to one or moreantibacterials other than the compounds of formula (I) described herein.The language “resistance” and “antibacterial resistance” refers tobacteria that are able to survive exposure to one or moreantibacterials. In some embodiments, the antibacterial-resistantbacteria include Streptococcus pyogenes, Streptococcus agalactiae,Streptococcus pneumoniae (including penicillin-resistant Streptococcuspneumoniae), Staphylococcus aureus (including vancomycin-resistantStaphylococcus aureus (VRSA)), methicillin-resistant Staphylococcusaureus (MRSA) (including hospital-acquired MRSA, community acquired MRSAand coagulase negative staphylocci) and Neisseria gonorrhoeae (includingpenicillin-resistant Neisseria gonorrhoeae, for example,chromosomally-mediated penicillin resistant Neisseria gonorrhoeae(CMRNG) and penicillinase-mediated resistant Neisseria gonorrhoeae(PPNG), cephalosporin-resistant Neisseria gonorrhoeae, for exampleceftriaxone-resistant Neisseria gonorrhoeae and cefixime-resistantNeisseria gonorrhoeae, quinolone-resistant Neisseria gonorrhoeae (QRNG),for example ciprofloxacin-resistant Neisseria gonorrhoeae,tetracycline-resistant Neisseria gonorrhoeae, for example,chromosomally-mediated tetracycline resistant Neisseria gonorrhoeae andplasmid-mediated penicillin resistant Neisseria gonorrhoeae,co-trimoxazole resistant Neisseria gonorrhoeae and aminoglycosideresistant Neisseria gonorrhoeae, for example, kanamycin resistantNeisseria gonorrhoeae and gentamicin resistant Neisseria gonorrhoeae,sulfonamide-resistant Neisseria gonorrhoeae and macrolide resistantNeisseria gonorrhoeae, for example, azithromycin resistant Neisseriagonorrhoeae).

In some embodiments, the Neisseria gonorrhoeae is multiple drugresistant Neisseria gonorrhoeae (MDRNG). The language “multiple drugresistant Neisseria gonorrhoeae” includes Neisseria gonorrhoeae that isresistant to two or more of antibiotics typically used for the treatmentof Neisseria gonffhoeae infections, for example, tetracycline,penicillin, cephalosporins (e.g., ceftriazone or cefixime), quinolones(e.g., norfloxacin, ciprofloxacin or ofloxacin), co-trimoxazole,sulfonamides, aminoglycosides (e.g., kanamycin or gentamicin) andmacrolides (e.g., azithromycin).

In one aspect, the invention provides a method for treating aGram-positive bacterial infection in a subject in need thereofcomprising administering an effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treating aGram-positive bacterial infection.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating a Gram-positive bacterial infection.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating a Gram-positive bacterial infection.

In one aspect, the invention provides a method for treating complicatedskin and skin structure infections in a subject in need thereofcomprising administering an effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treating acomplicated skin and skin structure infections.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating complicated skin and skin structureinfections.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating complicated skin and skin structureinfections.

The language “complicated skin and skin structure infections” includesinfections of the skin and the surrounding soft tissues that may requiresignificant surgical intervention, including, for example, infectedulcers, burns or major abscesses. In some embodiments, the complicatedskin and skin structure infections are caused by Streptococcus pyogenes,Streptococcus agalactiae, or Staphylococcus aureus, including MRSAand/or VRSA.

In one aspect, the invention provides a method for treating pneumonia ina subject in need thereof comprising administering an effective amountof a compound of formula (I), or a pharmaceutically acceptable saltthereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treatingpneumonia.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating pneumonia.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating pneumonia.

The term “pneumonia” refers to an inflammatory condition of the lungscaused by a bacterial infection. In some embodiments, the pneumonia iscaused by a Streptococcus pneumoniae or Staphylococcus aureus infection.In some embodiments, the pneumonia is nocosomial pneumonia (e.g.,hospital-acquired pneumonia) or community-acquired pneumonia. In someembodiments, the pneumonia is caused by penicillin-resistantStreptococcus pneumoniae.

In one aspect, the invention provides a method for treating aGram-negative bacterial infection in a subject in need thereofcomprising administering an effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treating aGram-negative bacterial infection.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating a Gram-negative bacterial infection.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating a Gram-negative bacterial infection.

In one aspect, the invention provides a method for treating an atypicalbacterial infection in a subject in need thereof comprisingadministering an effective amount of a compound of formula (I), or apharmaceutically acceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treating anatypical bacterial infection.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating a atypical bacterial infection.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating an atypical bacterial infection.

In one aspect, the invention provides a method for inhibiting bacterialDNA gyrase in a subject in need thereof, comprising administering aneffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for inhibitingbacterial DNA gyrase.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for inhibiting bacterial DNA gyrase.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for inhibiting bacterial DNA gyrase.

The language “bacterial DNA gyrase” refers to a bacterial type IItopoisomerase that introduces negative supercoils into DNA.

The language “effective amount” includes an amount of the compound offormula (I) that will elicit a biological or medical response of asubject, for example, the reduction or inhibition of enzyme or proteinactivity related to a bacterial DNA gyrase or a bacterial infection,amelioration of symptoms of a bacterial infection, or the slowing ordelaying of progression of a bacterial infection. In some embodiments,the language “effective amount” includes the amount of a compound offormula (I), that when administered to a subject, is effective to atleast partially alleviate, inhibit, and/or ameliorate a bacterialinfection or inhibit bacterial DNA gyrase, and/or reduce or inhibit thebacterial growth, replication or bacterial load of a bacteria in asubject.

In one aspect, the invention provides a method for treating a Neisseriagonorrhoeae infection in a subject in need thereof comprisingadministering an effective amount of a compound of formula (I), or apharmaceutically acceptable salt thereof.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, for treating aNeisseria gonorrhoeae infection.

In one aspect, the invention provides the use of a compound of formula(I), or a pharmaceutically acceptable salt thereof, in the manufactureof a medicament for treating a Neisseria gonorrhoeae infection.

In one aspect, the invention provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt thereof, for treating a Neisseria gonorrhoeae infection.

The term “subject” includes warm blooded mammals, for example, primates,cows, pigs, sheep, dogs, cats, rabbits, rats, and mice. In someembodiments, the subject is a primate, for example, a human. In someembodiments, the subject is suffering from a Gram-positive bacterialinfection. In some embodiments, the subject is in need of treatment(e.g., the subject would benefit biologically or medically fromtreatment). In some embodiments, the subject is suffering from asignificant underlying disease state that complicates the response totreatment of a bacterial infection, for example diabetes mellitus.

The language “inhibit,” “inhibition” or “inhibiting” includes a decreasein the baseline activity of a biological activity or process.

The language “treat,” “treating” and “treatment” includes the reductionor inhibition of enzyme or protein activity related to a bacterialinfection or bacterial DNA gyrase in a subject, amelioration of one ormore symptoms of a bacterial infection in a subject, or the slowing ordelaying of progression of a bacterial infection in a subject. Thelanguage “treat,” “treating” and “treatment” also includes the reductionor inhibition of the bacterial growth, replication or a reduction orinhibition of the bacterial load of bacteria in a subject.

Exemplification of the Invention

The invention is now illustrated by, but not limited to, the followingExamples:

Synthetic Methods

Unless otherwise stated:

-   -   (i) evaporations were carried out by rotary evaporation in vacuo        and work-up procedures were carried out after removal of        residual solids by filtration;    -   (ii) temperatures are quoted as ° C.; operations were carried        out at room temperature, that is typically in the range        18-26° C. and without the exclusion of air unless otherwise        stated, or unless the skilled person would otherwise work under        an inert atmosphere;    -   (iii) column chromatography (by the flash procedure) was used to        purify compounds and was performed on Merck Kieselgel silica        (Art. 9385) unless otherwise stated;    -   (iv) in general, the course of reactions was followed by TLC,        HPLC, or LC/MS and reaction times are given for illustration        only; yields are given for illustration only and are not        necessarily the maximum attainable;    -   (v) the structure of the end-products of the invention was        generally confirmed by NMR and mass spectral techniques. Proton        magnetic resonance spectra (¹H NMR) were generally determined        using a Bruker DRX-300 spectrometer or a Bruker DRX-400        spectrometer, operating at a field strength of 300 MHz, or 400        MHz, respectively. In cases where the NMR spectrum is complex,        only diagnostic signals are reported. Chemical shifts are        reported in parts per million downfield from tetramethylsilane        as an external standard (δ scale) and peak multiplicities are        shown thus: s, singlet; d, doublet; dd, doublet of doublets; dt,        doublet of triplets; dm, doublet of multiplets; t, triplet, m,        multiplet; br, broad. Chemical shifts are reported with errors        of ±0.1 ppm. Fast-atom bombardment (FAB) mass spectral data were        generally obtained using a Platform spectrometer (supplied by        Micromass) run in electrospray and, where appropriate, either        positive ion data or negative ion data were collected or using        Agilent 1100 series LC/MS equipped with Sedex 75ELSD, and where        appropriate, either positive ion data or negative ion data were        collected. The lowest mass major ion is reported for molecules        where isotope splitting results in multiple mass spectral peaks        (for example when chlorine is present). Reversed Phase HPLC was        carried out using YMC Pack ODS-AQ (100×20 mmID, S-5μ particle        size, 12 nm pore size) on Agilent instruments; and    -   (vi) each intermediate was purified to the standard required for        the subsequent stage and was characterized in sufficient detail        to confirm that the assigned structure was correct; purity was        assessed by HPLC (high-pressure liquid chromatography), TLC, or        NMR and identity was determined by infra-red spectroscopy (IR),        mass spectroscopy (MS) or NMR spectroscopy as appropriate.    -   (vii) compounds were named using ACD/Name (Release 12.00,        Product Version 12.01).

Intermediate 13-Chloro-6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-7-fluoro-1,2-benzoxazole-5-carbaldehyde

To an ice cooled solution of3-chloro-6,7-difluoro-1,2-benzoxazole-5-carbaldehyde (prepared accordingto the procedure described in International Application Publication No.WO 2010/043893, 5.0 g, 23.0 mmol) in anhydrous acetonitrile (50 ml) wasadded diisopropylethylamine (5.9 g, 45.9 mmol) followed bycis-2,6-dimethylmorpholine (2.6 g, 23.0 mmol) and the mixture was heatedat 85° C. for 12 hours in a sealed tube. The solution was cooled to roomtemperature and the volatiles were removed under vacuum. The residue wasdissolved in Ethyl acetate, washed with water followed by brine and thendried over anhydrous Na₂SO₄. Removal of solvent under vacuum affordedthe crude product, which was purified over silica gel column using agradient of ethyl acetate in pet. ether to give title compound as solid.Yield: 6.0 g (84%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.0 (d, 6H), 2.9 (t,2H), 3.1 (d, 2H), 3.8 (m, 2H), 7.7 (s, 1H), 10.2 (s, 1H). MS (ES) MH⁺:313 for C₁₄H₁₄ClFN₂O₃.

Intermediate 23-Chloro-5-(dimethoxymethyl)-6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-7-fluoro-1,2-benzoxazole

A solution of Intermediate 1 (3.0 g, 9.6 mmol) and a pinch ofp-toluenesulfonic acid in 2,2′-dimethoxy propane (15 mL) was heated at60° C. for 3 hours. Water (10 mL) was added to the reaction mixture atroom temperature. Extraction with ethyl acetate (3×10 mL), drying(Na₂SO₄) of the combined organic layers and removal of solvents undervacuum followed by trituration with cold diethyl ether (15 mL) affordedcrude product as a yellow solid. Yield: 2.7 g (80%). ¹H NMR (400 MHz,DMSO-d₆) δ: 1.1 (d, 6H), 2.8 (t, 2H), 3.0 (d, 2H), 3.3 (s, 6H), 3.8 (m,2H), 5.7 (s, 1H), 7.6 (s, 1H).

Intermediate 33-{5-(Dimethoxymethyl)-6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-7-fluoro-1,2-benzoxazol-3-yl}-1,3-oxazolidin-2-one

A solution of 2-oxazolidinone (0.18 g, 2.1 mmol) in dimethylformamide (1mL) was added slowly to a stirred suspension of NaH (0.06 g, 2.5 mmol)in dimethylformamide (1 mL) at 0° C. The mixture was stirred at the roomtemperature for 30 minutes, and a solution of Intermediate 2 (0.25 g,0.7 mmol) in dimethylformamide (3 mL) was added at the same temperature.This mixture was heated at 60° C. for 16 hours, poured into ice-cooledwater, and extracted with ethyl acetate (2×20 mL). The organic layerswere dried over anhydrous Na₂SO₄ and the solvents were removed undervacuum. The crude product was purified by silica gel columnchromatography using a gradient of ethyl acetate in pet. ether to affordthe title compound. Yield: 37 mg (13%). MS (ES) MH⁺: 410.4 forC₁₉H₂₄FN₃O₆.

Intermediate 43-Chloro-6-[(2R,6R)-2,6-dimethylmorpholin-4-yl]-7-fluoro-1,2-benzoxazole-5-carbaldehyde

To an ice cooled solution of3-chloro-6,7-difluoro-1,2-benzoxazole-5-carbaldehyde (prepared accordingto the procedure described in International Application Publication No.WO 2010/043893, 10.0 g, 46.0 mmol) in anhydrous acetonitrile (50 mL) wasadded diisopropylethylamine (11.9 g, 91.9 mmol) followed by(2R,6R)-2,6-dimethylmorpholine (5.2 g, 46.0 mmol) and the mixture washeated at 85° C. for 12 hours in a sealed tube. After cooling to roomtemperature, the volatiles were removed under vacuum. The residue wasdissolved in ethyl acetate (50 mL), washed with water (2×15 mL) followedby brine and then dried over anhydrous Na₂SO₄. Removal of solvent undervacuum afforded the crude product that was purified over silica gelcolumn using a gradient of ethyl acetate in pet. ether to give titlecompound as solid. Yield: 11.0 g (76%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.2(d, 6H), 3.0 (m, 2H), 3.4 (m, 2H), 4.1 (m, 2H), 8.0 (s, 1H), 10.3 (s,1H). ES MH⁺: 313.3 for C₁₄H₁₄ClFN₂O₃.

Intermediate 53-Chloro-5-(dimethoxymethyl)-6-((2R,6R)-2,6-dimethylmorpholino)-7-fluorobenzo[d]isoxazole

A mixture of Intermediate 4 (14.42 g, 46.10 mmol), 2,2-dimethoxypropane(57.4 ml, 461.00 mmol) and p-toluenesulfonic acid (0.088 g, 0.46 mmol)was stirred at room temperature for 16 hours. The reaction was quenchedwith the addition of saturated aqueous NaHCO₃ solution and extractedwith ethyl acetate. The organic layer was washed with water, brine, anddried over Na₂SO₄. The filtrate was concentrated under vacuum to givethe title compound (15.35 g, 90%). MS (ES) MH⁺: 359 for C₁₆H₂₀ClFN₂O₄.

Intermediate 63-(5-(Dimethoxymethyl)-6-((2R,6R)-2,6-dimethylmorpholino)-7-fluorobenzo[d]isoxazol-3-yl)oxazolidin-2-one

Oxazolidin-2-one (purchased from Sigma-Aldrich, 728 mg, 8.36 mmol) in 1dimethylformamide (1 mL) was added to a suspension of NaH (290 mg, 7.25mmol, 60% in mineral oil) in dimethylformamide (1 mL), and the mixturewas stirred at room temperature for 10 minutes. Intermediate 5 (2.0 g,5.57 mmol) in dimethylformamide (2 mL) was added slowly. The resultingmixture was heated at 80° C. for 5 hours before being cooled and pouredinto ice cold aqueous NH₄Cl, and extracted with ethyl acetate. Theorganic layer washed with water, brine, and dried (Na₂SO₄). Afterconcentration, the residue was purified on a silica gel column (elution20-50% ethyl acetate in CHCl₃) to give the title compound (800 mg, 35%).¹H NMR (300 MHz, DMSO-D6) δ: 1.2 (br s, 6H) 2.7-2.9 (m, 2H) 3.06-3.35(m, 8H) 3.9-4.25 (m, 4H) 4.45-4.7 (m, 2H) 5.7 (s, 1H) 8.35 (s, 1H). MS(ES) MH⁺: 410 for C₁₉H₂₄FN₃O₆.

Intermediate 73-Chloro-6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazole

A solution of Intermediate 1 (16.3 g, 52.2 mmol), ethylene glycol (8.1g, 130.6 mmol) and pyridinium p-toluenesulfonate (1.31 g, 5.2 mmol) intoluene (300 mL) was heated at reflux in a Dean-Stark apparatus for 16hours. The solvents were removed under vacuum and the residue wasdissolved in diethyl ether (75 mL), washed with water (3×25 mL) andaqueous brine (25 mL). The organic layers were dried over anhydrousNa₂SO₄ and filtered. Removal of solvents under vacuum afforded the titlecompound, which was further purified by trituration with hot hexane.Yield: 18.0 g (80%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.1 (d, 6H), 2.8 (t,2H), 3.0 (d, 2H), 3.3 (m, 4H), 3.8 (m, 2H), 5.7 (s, 1H), 7.6 (s, 1H).

Intermediate 8(4R)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-methyl-1,3-oxazolidin-2-one

To a stirred solution of NaH (0.24 g, 9.9 mmol) in dimethylformamide (10mL), a solution of (4R)-4-methyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Nishiyama, T.; Matsui, Shigeki;Yamada, F. J. Het. Chem. (1986), 23(5), 1427-9) (1.0 g, 9.9 mmol) indimethylformamide (10 mL) was added slowly at 0° C. over a period of 10minutes. The mixture was stirred at the room temperature for 30 minutesand a solution of Intermediate 7 (1.1 g, 3.1 mmol) in dimethylformamide(5 mL) was added at the same temperature. This mixture was heated at 80°C. for 12 hours and poured into ice-cooled water and extracted withethyl acetate (2×20 mL). The organic layers were dried over anhydrousNa₂SO₄ and the solvents were removed under vacuum. The crude product waspurified by silica gel column chromatography using a gradient of ethylacetate in pet. ether. Yield: 0.15 g (12%). MS (ES) MH⁺: 422.4 forC₂₀H₂₄FN₃O₆.

Intermediates 9 and 10 were prepared from Intermediate 7 and theindicated oxazolidinone starting material using a method similar to theone described for the synthesis of Intermediate 8.

Intermediate 9(5S)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-methyl-1,3-oxazolidin-2-one

Starting material: (5S)-5-methyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Rein, K.; Goicoechea-Pappas, M.;Anklekar, T. V.; Hart, G. C.; Smith, G. A.; Gawley, R. E. JACS (1989),111(6), 2211-17). MS (ES) MH⁺: 422.4 for C₂₀H₂₄FN₃O₆.

Intermediate 10(5R)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-methyl-1,3-oxazolidin-2-one

Starting material: (5R)-5-methyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Chouhan, G.; Alper, H. J. Org.Chem. (2009), 74(16), 6181-6189). MS (ES) MH⁺: 422.4 for C₂₀H₂₄FN₃O₆.

Intermediate 113-Chloro-6-[(2R,6R)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazole

A solution of Intermediate 4 (11.0 g, 35.3 mmol), ethylene glycol (5.7g, 91.9 mmol) and pyridinium p-toluenesulfonic acid (0.92 g, 3.7 mmol)in toluene was heated at reflux in a Dean-Stark apparatus for 16 hours.The solvents were removed under vacuum and the residue was dissolved indiethyl ether (75 mL), washed with water (3×25 mL) followed by brinesolution (25 mL). The organic layers were dried over anhydrous Na₂SO₄and filtered. Removal of solvents under vacuum afforded the titlecompound, which was further purified by trituration with hot hexane.Yield: 9.0 g (72%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.2 (d, 6H), 2.9 (m,2H), 3.2 (d, 2H), 4.05 (m, 4H), 4.15 (m, 2H), 6.2 (s, 1H), 7.7 (s, 1H).MS (ES) MH⁺: 357.3 for C₁₆H₁₈ClFN₂O₄.

Intermediate 12(R)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-5-methyloxazolidin-2-one

(R)-5-Methyloxazolidin-2-one (1.134 g, 11.21 mmol, synthesized accordingto the procedure described in Chouhan, G.; Alper, H. J. Org. Chem.(2009), 74(16), 6181-6189) in dimethylformamide (10 mL) was added to asuspension of NaH (0.448 g, 11.21 mmol, 60% in mineral oil) indimethylformamide (10 mL). The mixture was stirred at room temperaturefor 30 minutes. Intermediate 11 (4 g, 11.2 mmol) in dimethylformamide(10 mL) was added slowly, and the resulting mixture was heated at 80° C.for 2 hours. The reaction was cooled, poured into ice cold aqueous NH₄Cland extracted with ethyl acetate. The organic layer washed with water,brine, and dried. The crude product after concentration was purified ona silica gel column (elution 40-50% ethyl acetate in hexanes) to givethe title compound. ¹H NMR (300 MHz, DMSO-d₆) δ: 1.2 (d, 6H), 1.5 (d,3H), 2.8-3.3 (m, 4H), 3.7-4.3 (m, 8H), 4.9-5.1 (m, 1H), 6.2 (s, 1H), 8.4(s, 1H). MS (ES) MH⁺: 422 for C₂₀H₂₄FN₃O₆.

Intermediate 13 2-(2,3,4-Trifluorophenyl)-1,3-dioxolane

Ethylene glycol (348.7 g, 5.62 mol) was added in one portion to astirred mixture of 2,3,4-trifluorobenzaldehyde (300.0 g, 1.87 mol) andp-toluenesulfonic acid monohydrate (35.6 g, 0.18 mol) in toluene (4.5 L)at ambient temperature. The resulting mixture was heated at reflux withazeotropic removal of water using a Dean-Stark apparatus. The water wasremoved from time to time (3 hour intervals). After 24 hours, thetoluene was removed and the residue was diluted with ethyl acetate (1.5L) and washed with saturated aqueous NaHCO₃ (2×750 mL), water (2×500 mL)and brine solution (500 mL). The organic layers were dried over sodiumsulphate and the solvent was removed under vacuum. The crude product wassubjected to distillation at 60-70° C. in high vacuum (0.1 mm of Hg) toremove the starting material and impurities. The fraction obtained at75-85° C. (0.1 mm of Hg) is consistent the title compound. Yield: 300.0g (78%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.9-4.1 (m, 4H), 6.0 (s, 1H),7.3-7.4 (m, 2H).

Intermediate 14 5-(1,3-Dioxolan-2-yl)-2,3,4-trifluorobenzaldehyde

n-Butyllithium (2.5 M solution in hexane, 300 mL, 0.75 mol) was addeddrop wise to a solution of Intermediate 13 (118.0 g, 0.57 mol) intetrahydrofuran (2.3 L) at −70° C. over 45 minutes, and the mixture wasstirred at that temperature for a an hour. Dimethylformamide (236 mL,3.27 mol) was added drop wise over a period of 30 minutes stirring at−70° C. and stirring was continued at the same temperature for 1 hourbefore quenching with saturated aqueous NH₄Cl solution at 0° C. Themixture was extracted with ethyl acetate (2×500 mL) and the organiclayers were washed with water (2×500 mL), brine (500 mL) and dried overNa₂SO₄. The crude product was purified by silica gel (60-120 mesh) flashcolumn chromatography using gradient of 10% ethyl acetate in pet. ether.Yield: 125.0 g (93%). ¹H NMR (400 MHz, DMSO-d₆) δ: 4.0-4.1 (m, 4H), 6.05(s, 1H), 7.8 (m, 1H), 10.1 (s, 1H).

Intermediate 151-[5-(1,3-Dioxolan-2-yl)-2,3,4-trifluorophenyl]-N-hydroxymethanimine

Pyridine (95.3 g, 1.2 mol) and hydroxylamine hydrochloride (62.8 g, 0.90mol) were added sequentially to a stirred solution of Intermediate 14(140.0 g, 0.60 mol) in ethanol (1500 mL) at 0° C. The mixture wasstirred at the room temperature for 18 hours. The volatiles were removedunder vacuum and the residue was diluted with ethyl acetate (2.0 L) andwashed with water (2×500 mL), brine (2×500 mL) and dried over sodiumsulphate. Solvents were removed to obtain the crude product that waspurified by washing with a mixture of diethyl ether and heptane (1:9).Yield: 100.0 g (1^(st) crop). 20 g of the product was also obtained bysilica gel column purification of the mother liquor obtained from the1^(st) crop using gradient of ethyl acetate in pet ether. Total yield:120.0 g (80%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.95-4.1 (m, 4H), 6.0 (s,1H), 7.6 (m, 1H), 8.2 (s, 1H), 11.8 (s, 1H).

Intermediate 165-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N-hydroxybenzimidoyl chloride

N-Chlorosuccinimide (49.0 g, 0.36 mol) was added in portions to astirred solution of Intermediate 15 (70.0 g, 0.28 mol) indimethylformamide (360 mL) at ambient temperature under an atmosphere ofN₂. After stirring for 4 hours, N₂ was bubbled through the reactionmixture for 30 minutes before and pouring the mixture into ice water (2L). The resultant mixture was stirred for 1 hour and the solids werefiltered and washed with water (2×250 mL). The solids were stirred intoluene (300 mL) for 30 min and filtered to obtain 53.0 g as a 1^(st)crop. The toluene filtrate was treated with heptane (400 ml)precipitating additional solids that were filtered and washed withadditional heptane (50 mL) affording 7 g as 2^(nd) crop. Total yield:60.0 g (76%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.95-4.1 (m, 4H), 6.0 (s,1H), 7.6 (m, 1H), 12.8 (s, 1H).

Intermediate 17(2R)-1-[[5-(1,3-Dioxolan-2-yl)-6,7-difluoro-1,2-benzoxazol-3-yl]amino]propan-2-ol

(R)-1-aminopropan-2-ol (1.3 ml, 16.6 mmol) was added to a solution ofIntermediate 16 (2.22 g, 7.88 mmol) in dimethylformamide (30 mL) atambient temperature. There was a slow exotherm for the reaction. Afterstirring for 10 minutes, LC-MS showed consumption of starting materialwith a new intermediate material (MH⁺=321). After stirring for 30minutes more, potassium tert-butoxide (1.77 g, 15.8 mmol) was added allat once. A slow exotherm ensued. After stirring for 1 hour, LC-MS showedconversion to material consistent with the title compound (MH⁺=301) withsome intermediate material consistent (MH⁺=321) remaining. Additionalpotassium tert-butoxide was added (400 mg, 3.6 mmol), and the mixturewas stirred at room temperature for 1 hour. LC-MS showed completeconversion to material with MH⁺=321. The mixture was quenched withaqueous NH₄Cl, and solvent was removed in vacuo. The solid residue wastaken up in water (50 mL) while breaking up the solid mass, and themixture was stirred at ambient temperature overnight. The solids werefiltered and rinsed through with water before being dried in vacuo togive material consistent with the title compound. Yield 2.24 g (95%). ¹HNMR (400 MHz, DMSO-d₆) δ: 1.1 (d, 3H) 3.2 (t, 2H) 3.8-4.0 (m, 1H)4.0-4.1 (m, 4H) 4.8 (d, 1H) 6.1 (s, 1H) 7.3 (t, 1H) 8.0 (dd, 1H). ESMH⁺: 301 for C₁₃H₁₄F₂N₂O₄.

Intermediate 18(R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-5-methyloxazolidin-2-one

A mixture of Intermediate 17 (500 mg, 1.67 mmol),di(1H-imidazol-1-yl)methanone (405 mg, 2.50 mmol), anddimethylaminopyridine (102 mg, 0.83 mmol) in tetrahydrofuran (10 mL) washeated at reflux overnight (21 hours). The solvent was removed to affordan oily residue. The residue was taken up in 1N HCl, and the mixture wasstirred at ambient temperature for 90 minutes affording solids. Thesolids were filtered and rinsed well with water breaking them up with aspatula before drying in vacuo. The material is consistent with thetitle compound with about 5% impurity due to hydrolysis to correspondingaldehyde. Yield 407 mg (75%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.5 (d, 3H)3.8 (dd, 1H) 4.0-4.1 (m, 4H) 4.3 (t, 1H) 5.0 (m, 1H) 6.1 (s, 1H) 8.45(d, 1H). ES MH⁺: 327 for C₁₄H₁₂F₂N₂O₅;

Intermediate 19(R)-6,7-Difluoro-3-(5-methyl-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

A solution of Intermediate 18 (404 mg, 1.24 mmol) in HCl (1.0 M inwater) (10 mL, 10.00 mmol) and tetrahydrofuran (10 mL) was stirred atroom temperature for 3 days. The reaction mixture was diluted with waterand extracted 2 times with ethyl acetate and each extract was washedwith brine. The organic layers were combined and dried over MgSO₄,filtered and evaporated to afford material as an off-white solidconsistent with the title compound. Yield 350 mg (100%). ¹H NMR (300MHz, CDCl₃) δ: 1.6 (d, 3H) 3.8 (dd, 1H) 4.3 (dd, 1H) 4.9 (m, 1H) 8.9(dd, 1H) 10.2 (s, 1H). ES MH⁺: 283 for C₁₂H₈F₂N₂O₄.

Intermediate 206-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((R)-5-methyl-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

A mixture of Intermediate 19 (92 mg, 0.33 mmol),(2R,6R)-2,6-dimethylmorpholine (45.1 mg, 0.39 mmol) and K₂CO₃ inbutyronitrile (3 mL) and water (0.5 mL) was heated at 100° C. in amicrowave reactor vessel. The solvent was removed and the residuediluted with water and extracted 2 times with ethyl acetate with eachextract being washed with brine. The organic layers were combined anddried over MgSO₄, filtered and evaporated to afford material that waschromatographed on silica gel (50% hexanes in CH₂CH₂ followed bygradient elution to 100% CH₂CH₂) to afford a yellow solid consistentwith the title compound. Yield 100 mg (81%). ¹H NMR (300 MHz, CDCl₃) δ1.2 (d, 6H) 1.5 (d, 3H) 2.9-3.0 (m, 2H) 3.4 (dt, 2H) 3.7 (dd, 1H)4.1-4.3 (m, 3H) 4.8-5.0 (m, 1H) 8.7 (d, 1H) 10.3 (s, 1H). MS (ES) MH⁺:378 for C₁₈H₂₀FN₃O₅.

Intermediate 21(4S)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-methyl-1,3-oxazolidin-2-one

Intermediate 21 was prepared from Intermediate 7 using(4S)-4-methyl-1,3-oxazolidin-2-one (synthesized according to theprocedure described in Nishiyama, T.; Matsui, Shigeki; Yamada, F. J.Het. Chem. (1986), 23(5), 1427-9) in a method similar to the onedescribed for the synthesis of Intermediate 8. MS (ES) MH⁺: 422.4 forC₂₀H₂₄FN₃O₆.

Intermediate 22(S)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-4-methyloxazolidin-2-one

Intermediate 22 was prepared from Intermediate 11 and(4S)-4-methyl-1,3-oxazolidin-2-one (synthesized according to theprocedure described in Nishiyama, T.; Matsui, Shigeki; Yamada, F. J.Het. Chem. (1986), 23(5), 1427-9) using a method similar to the onedescribed for the synthesis of Intermediate 12. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.2 (d, 6H), 1.35-1.5 (m, 3H), 2.8-3.3 (m, 4H), 3.9-4.3 (m,7H), 4.6-4.8 (m, 2H), 6.0-6.3 (m, 1H), 6.2 (s, 1H), 8.2 (s, 1H). MS (ES)MH⁺: 422. for C₂₀H₂₄FN₃O₆.

Intermediates 23-29 were prepared from Intermediate 7 and the indicatedoxazolidinone starting material using a method similar to the onedescribed for the synthesis of Intermediate 8.

Intermediate 23(4S)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-ethyl-1,3-oxazolidin-2-one

Starting material: (4S)-4-ethyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Begis, G.; Cladingboel, D. E.;Jerome, L.; Motherwell, W. B.; Sheppard, T. D. Eur. J. Org. Chem.(2009), (10), 1532-1548). MS (ES) MH⁺: 436.4 for C₂₁H₂₆FN₃O₆.

Intermediate 24(4R)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-ethyl-1,3-oxazolidin-2-one

Starting material:(4R)-4-ethyl-1,3-oxazolidin-2-one-(5R)-5-methyl-1,3-oxazolidin-2-one(synthesized according to the procedure described in Chouhan, G.; Alper,H. J. Org. Chem. (2009), 74(16), 6181-6189). MS (ES) MH⁺: 436.4 forC₂₁H₂₆FN₃O₆.

Intermediate 25(4R)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-phenyl-1,3-oxazolidin-2-one

Starting material: (4R)-4-phenyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Begis, G.; Cladingboel, D. E.;Jerome, L.; Motherwell, W. B.; Sheppard, T. D. Eur. J. Org. Chem.(2009), (10), 1532-1548). MS (ES) MH⁺: 484.5 for C₂₅H₂₆FN₃O₆.

Intermediate 26(4S)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-phenyl-1,3-oxazolidin-2-one

Starting material: (4S)-4-phenyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in MacNevin, C. J.; Moore, R. L.;Liotta, D. C. J. Org. Chem. (2008), 73(4), 1264-1269). MS (ES) MH⁺:484.5 for C₂₅H₂₆FN₃O₆.

Intermediate 27(4R)-4-Benzyl-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-1,3-oxazolidin-2-one

Starting material: (4R)-4-benzyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Paz, J.; Perez-Balado, C.;Iglesias, B.; Munoz, L. J. Org. Chem. (2010), 75(9), 3037-3046). MS (ES)MH⁺: 498.5 for C₂₆H₂₈FN₃O₆.

Intermediate 28(4S)-4-Benzyl-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-1,3-oxazolidin-2-one

Starting material: (4S)-4-benzyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Begis, G.; Cladingboel, D. E.;Jerome, L.; Motherwell, W. B.; Sheppard, T. D. Eur. J. Org. Chem.(2009), (10), 1532-1548). MS (ES) MH⁺: 498.5 for C₂₆H₂₈FN₃O₆.

Intermediate 293-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5,5-dimethyl-1,3-oxazolidin-2-one

Starting material: 5,5-dimethyl-1,3-oxazolidin-2-one (synthesizedaccording to the procedure described in Jones, S.; Smanmoo, C. Tet.Lett. (2004), 45(8), 1585-1588). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.1 (d,6H), 1.5 (s, 6H), 2.8 (t, 2H), 3.1 (d, 2H), 3.8 (m, 2H), 4.0 (m, 4H),4.1 (m, 2H), 6.1 (s, 1H), 8.4 (s, 1H). MS (ES) MH⁺: 436.4 forC₂₁H₂₆FN₃O₆.

Mixture of Intermediates 30 and 31(5R)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-ethyl-1,3-oxazolidin-2-oneand(5S)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-ethyl-1,3-oxazolidin-2-one

Intermediates 30 and 31 were prepared from Intermediate 11 and5-ethyl-1,3-oxazolidin-2-one (synthesized according to the proceduredescribed in European Patent Application Publication No. EP 244810)using a method similar to the one described for the synthesis ofIntermediate 12. The diastereomers were separated via HPLC usingChiralpak IC (250×4.6) mm (hexane:ethanol, 80:20, 1.0 ml/min).

Intermediate 30((5R)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-ethyl-1,3-oxazolidin-2-one)was the first eluting diastereomer. R_(T)=16.2 min; ¹H NMR (400 MHz,DMSO-d₆) δ: 1.0 (t, 3H), 0.95-1.0 (m, 6H), 1.8 (m, 2H), 2.9 (m, 2H), 3.2(m, 2H), 3.8 (dd, 1H), 4.0 (m, 2H), 4.0-4.05 (m, 4H), 4.2 (t, 1H), 6.2(s, 1H), 8.4 (s, 1H). MS (ES) MH⁺: 436.4 for C₂₁H₂₆FN₃O₆.

Intermediate 31((5S)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-ethyl-1,3-oxazolidin-2-one)was second eluting diastereomer. R_(T)=18.9 min; ¹H NMR (400 MHz,DMSO-d₆) δ: 1.0 (t, 3H), 0.95-1.0 (m, 6H), 1.8 (m, 2H), 2.9 (m, 2H), 3.2(m, 2H), 3.8 (dd, 1H), 4.0 (m, 2H), 4.0-4.05 (m, 4H), 4.2 (t, 1H), 6.2(s, 1H), 8.4 (s, 1H). MS (ES) MH⁺: 436.4 for C₂₁H₂₆FN₃O₆.

Intermediate 32(4R)-4-({[tert-Butyl(dimethyl)silyl]oxy}methyl)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-1,3-oxazolidin-2-one

A solution of(4R)-4-({[tert-butyl(diphenyl)silyl]oxy}methyl)-1,3-oxazolidin-2-one(synthesized according to the procedure described in Berkowitz, D. B.;Sloss, D. G. J. Org. Chem. (1995), 60(21), 7047-50) in dimethylformamide(15 mL) was added to a stirred solution of NaH (0.83 g, 34.6 mmol) indimethylformamide (10 mL) at 0° C. over a period of 10 minutes. Themixture was stirred at the room temperature for 30 minutes and asolution of Intermediate 7 (6.17 g, 17.3 mmol) in dimethylformamide (25mL) was added at the same temperature. This mixture was heated at 60° C.for 2 hours and poured into ice-cooled water, extracted with ethylacetate (2×20 mL). The organic layers were dried over anhydrous Na₂SO₄and the solvents were removed under vacuum. The crude product waspurified by silica gel column chromatography using a gradient of ethylacetate in pet. ether. Yield: 1.2 g (13%). ¹H NMR (400 MHz, DMSO-d₆) δ:−0.2 (s, 3H), −0.1 (s, 3H), 0.75 (s, 9H), 1.1 (d, 6H), 2.8 (t, 2H), 3.1(d, 2H), 3.7 (m, 3H), 4.0 (m, 2H), 4.0-4.1 (m, 2H), 4.1 (d, 1H), 4.4 (d,1H), 4.7 (d, 2H), 6.1 (s, 1H), 8.3 (s, 1H). MS (ES) MH⁺: 552.6 forC₂₆H₃₈FN₃O₇Si.

Mixture of Intermediates 33 and 34(4S)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(hydroxymethyl)-1,3-oxazolidin-2-oneand(4R)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(hydroxymethyl)-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 32 (1.5 g, 2.7 mmol) intetrahydrofuran (50 mL), 1M solution of tetrabutylammonium fluoride intetrahydrofuran (1.4 g, 5.4 mmol) was added at 0° C., and the mixturewas stirred at the room temperature for 10 minutes. Water (3 mL) wasadded to the reaction mixture and the organic layer was separated anddried over anhydrous Na₂SO₄. Evaporation of the solvent under vacuumafforded a solid that was a 68%+27% mixture of enantiomers by chiralHPLC analysis. Yield: 1.1 g (92%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.1 (d,6H), 2.8 (t, 2H), 3.1 (d, 2H), 3.5-3.6 (m, 1H), 3.7-3.8 (m, 2H), 3.9-4.0(m, 3H), 4.05-4.1 (m, 2H), 4.5 (dd, 1H), 4.6-4.65 (m, 2H), 5.2 (t, 1H),6.1 (s, 1H), 8.3 (s, 1H). MS (ES) MH⁺: 438.4 for C₂₀H₂₄FN₃O₇.

The R and S enantiomers of Mixture of Intermediates 33 and 34 wereseparated by chiral HPLC using Chiralpak IC (250×4.6 mm) column(hexane:ethanol (80:20); 1.0 mL/min) to afford 2 components,Intermediate 33 as the major component and Intermediate 34 as the minorcomponent.

Intermediate 33((4S)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(hydroxymethyl)-1,3-oxazolidin-2-one)was the first eluting enantiomer. R_(T)=10.86 min; yield: 550 mg. MS(ES) MH⁺: 438.4 for C₂₀H₂₄FN₃O₇.

Intermediate 34((4R)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(hydroxymethyl)-1,3-oxazolidin-2-one)was the second eluting enantiomer. R_(T)=14.99 min; yield: 420 mg. MS(ES) MH⁺: 438.4 for C₂₀H₂₄FN₃O₇.

Intermediate 35(4R)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(fluoromethyl)-1,3-oxazolidin-2-one

Diethylaminosulfur trifluoride (1.0 g, 6.3 mmol) was added to a stirredsolution of Intermediate 33 (0.55 g, 1.25 mmol) in tetrahydrofuran (25mL) at −78° C., and the mixture was stirred for 1 hour before warming toroom temperature for 1 hour. Methanol (1 mL) was added, and thevolatiles were removed under vacuum. The residue was dissolved in ethylacetate (15 mL) and washed with saturated NaHCO₃ (5 mL), water (10 mL)and aqueous brine. The organic layer was dried over Na₂SO₄, and thesolvent was removed under vacuum to afford the title compound as asolid. Yield: 0.44 g (80%). MS (ES) MH⁺: 440.4 for C₂₀H₂₃F₂N₃O₆.

Intermediate 36(4S)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(fluoromethyl)-1,3-oxazolidin-2-one

Intermediate 36 was prepared from Intermediate 34 using a method similarto the one described for the synthesis of Intermediate 35. MS (ES) MH⁺:440.4 for C₂₀H₂₃F₂N₃O₆.

Mixture of Intermediates 37 and 38(4R)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(methoxymethyl)-1,3-oxazolidin-2-oneand(4S)-3-{6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(methoxymethyl)-1,3-oxazolidin-2-one

A mixture of Intermediates 33 and 34, 0.55 g, 1.3 mmol) and methyliodide (0.54 g, 3.8 mmol) were added to a stirred mixture of NaH (0.06g, 2.5 mmol) in dimethylformamide (5 mL) at 0° C., and the resultantmixture was stirred at the room temperature for an hour. The reactionmixture was quenched with saturated aqueous NH₄Cl (5 ml) and extractedwith ethyl acetate (3×10 ml). The combined organic layers were washedwith water and dried over Na₂SO₄. Evaporation of the solvent undervacuum afforded the crude title compound which was purified by flashcolumn silica gel chromatography using a gradient of ethyl acetate inpet.ether. Yield: 0.4 g (70%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.1 (d, 6H),2.8 (t, 2H), 3.1 (d, 2H), 3.2 (s, 3H), 3.5 (dd, 1H), 3.7-3.75 (m, 2H),3.9 (d, 1H), 3.9-34.0 (m, 2H), 4.0-4.1 (m, 2H), 4.4 (dd, 1H), 4.6-4.7(m, 2H), 6.1 (s, 1H), 8.3 (s, 1H). MS (ES) MH⁺: 452.4 for C₂₁H₂₆FN₃O₇.

Intermediate 39 (4S)-4-(Methoxymethyl)-1,3-oxazolidin-2-one

To a stirred solution oftert-butyl[(2R)-1-hydroxy-3-methoxypropan-2-yl]carbamate (synthesizedaccording to the procedure described in Sowinski, J. A.; Toogood, P. L.J. Org. Chem. (1996), 61(22), 7671-7676) (8.3 g, 40.4 mmol)tetrahydrofuran (100 mL), 1M solution of potassium t-butoxide intetrahydrofuran (80.9 mL, 80.9 mmol) was added dropwise at 0° C. and themixture was stirred at the room temperature for 2 hours. Water (20 ml)was added to the reaction mixture and extracted with ethyl acetate (3×50ml). The combined organic layers were washed with brine and dried overNa₂SO₄. Yield: 5.0 g (94%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.3 (s, 3H),3.3 (m, 2H), 3.9 (m, 1H), 4.0 (dd, 1H), 4.3 (t, 1H), 7.7 (d, 1H).[α]_(D) ²⁵=−5.876.

Intermediate 40(4S)-3-{6-[(2R,6S)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(methoxymethyl)-1,3-oxazolidin-2-one

Intermediate 40 was prepared from Intermediate 39 and Intermediate 7using a method similar to the one described for the synthesis ofIntermediate 32. ¹H NMR (400 MHz, DMSO-d₆) δ: 1.1 (d, 6H), 2.8 (t, 2H),3.1 (d, 2H), 3.2 (s, 3H), 3.5 (dd, 1H), 3.7-3.75 (m, 2H), 3.9 (d, 1H),3.95-4.0 (m, 2H), 4.0-4.1 (m, 2H), 4.4 (dd, 1H), 4.45-4.7 (m, 2H), 6.1(s, 1H), 8.3 (s, 1H). MS (ES) MH⁺: 452.4 for C₂₁H₂₆FN₃O₇.

Intermediate 41(S)-5-((tert-Butyldiphenylsilyloxy)methyl)oxazolidin-2-one

(S)-5-(hydroxymethyl)oxazolidin-2-one (570 mg, 4.87 mmol, as describedby Danielmeier, K.; Steckhan, E. Tet. Asymmetry, 6(5), 1995, 1181) andimidazole (331 mg, 4.87 mmol) were dissolved in dimethylformamide (5 mL)and cooled to 0° C. tert-Butylchlorodiphenylsilane (1.34 g, 4.87 mmol)was added dropwise at 0° C. The reaction mixture was allowed to warm toroom temperature and stirred for 5 hours. The mixture was was pouredinto 0.5 N HCl (50 ml), and the resultant mixture was extracted withethyl acetate. The layers were separated, and the organic phase waswashed with saturated sodium bicarbonate, water and brine. The organicphase was dried over sodium sulfate and the solvent removed to affordcrude material that was purified on a silica gel column (50% ethylacetate in hexanes) to give the title compound (1.28 g, 74.0%). ¹H NMR(300 MHz, DMSO-d₆) δ: 1.0 (s, 9H) 3.3-3.6 (m, 2H) 3.6-3.9 (m, 2H)4.6-4.8 (m, 1H) 7.3-7.8 (m, 11H). MS (ES) (M+23)⁺: 278 for the Na⁺adduct of C₂₀H₂₅NO₃Si.

Intermediate 42(S)-5-((tert-Butyldiphenylsilyloxy)methyl)-3-(6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)oxazolidin-2-one

Intermediate 42 was prepared from Intermediate 41 and Intermediate 11using a method similar to the one described for the synthesis ofIntermediate 32. ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9 (s, 9H) 1.2 (d, 6H)2.9 (dd, 2H) 3.2-3.3 (m, 2H) 3.8-4.1 (m, 9H) 4.3 (t, 1H) 4.95-5.1 (m,1H) 6.2 (s, 1H) 7.3-7.7 (m, 10H) 8.5 (s, 1H). MS (ES) MH⁺: 676 forC₃₆H₄₂FN₃O₇Si.

Intermediate 43(S)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-5-(hydroxymethyl)oxazolidin-2-one

Acetic acid (0.89 mL, 15.5 mmol) and a solution of 1M tetrabutylammoniumfluoride (3.1 mL, 3.1 mmol) in tetrahydrofuran were added sequentiallyto a solution of Intermediate 42 (2.1 g, 3.11 mmol) dissolved in 15 mLof tetrahydrofuran. The mixture was stirred at room temperature for 18hours. The reaction mixture was diluted with water and extracted withethyl acetate, which was concentrated to afford crude material that waspurified on a silica gel column (50-70% ethyl acetate gradient inhexanes) to give the title compound (1.33 g, 98% yield). ¹H NMR (300MHz, DMSO-d₆) δ: 1.2 (d, 6H) 2.8-3.3 (m, 4H) 3.5-3.8 (m, 2H) 3.9-4.3 (m,8H) 4.7-5.05 (m, 1H) 6.2 (s, 1H) 8.4 (s, 1H). MS (ES) MH⁺: 438 forC₂₀H₂₄FN₃O₇.

Intermediate 44(S)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-5-(fluoromethyl)oxazolidin-2-one

Intermediate 44 was prepared from Intermediate 43 using a method similarto the one described for the synthesis of Intermediate 35. ¹H NMR (300MHz, CDCl₃) δ: 1.3 (d, 6H) 3.0 (dd, 2H) 4.0-4.2 (m, 8H) 4.3 (t, 1H)4.55-4.9 (m, 3H) 5.0-5.25 (m, 1H) 6.3 (s, 1H) 8.5 (s, 1H). MS (ES) MH⁺:440 for C₂₀H₂₃F₂N₃O₆.

Intermediate 45 3-Chloro-4-fluoro-2-hydroxybenzoic acid

Sodium hydroxide (208 g, 5.21 mol) was added in portions to a stirredsolution of 3-chloro-2,4-difluorobenzoic acid (200 g, 1.04 mol) in1,3-dimethyl imidazolidin-2-one (1 L), and the mixture was heated to140° C. for 2 hours. The reaction mixture was cooled to room temperatureand neutralized with ice-cooled 2N HCl (350 mL) precipitating a whitesolid that was collected by filtration. The filtered solid was dissolvedin methyl t-butyl ether (500 mL), washed with saturated brine solution(150 mL) and dried over Na₂SO₄. Removal of solvent under vacuum affordedthe title compound as off white solid. Yield: 180 g (91%). ¹H NMR (300MHz, MeOH-d₄) δ: 6.8 (t, 1H), 7.90 (dd, 1H), 11.3 (s, 1H). MS (ES) MH⁻:189 for C₇H₄ClFO₃.

Intermediate 46 Methyl 3-chloro-4-fluoro-2-hydroxybenzoate

Oxalyl chloride (75.9 g, 0.60 mol) and dimethylformamide (1 mL) wereadded sequentially to an ice cooled and stirred solution of Intermediate45 (57.0 g, 0.29 mol) in dry dichloromethane (570 mL), and the mixturewas stirred at the room temperature for 16 hours. Volatiles were removedunder vacuum affording a yellow solid to which methanol (350 mL) wasadded at 0° C., and the resultant mixture was stirred at the sametemperature for 1 hour. The reaction mixture was poured slowly into anice-cooled solution of 2N HCl (1.0 L) precipitating a solid that wascollected by filtration. This wet solid was dissolved in diethyl ether(1.5 L), which was separated and dried over Na₂SO₄. Removal of thesolvent under vacuum afforded the title compound as white solid. Yield:58.0 g (95%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.9 (s, 3H), 7.0 (t, 1H), 7.8(dd, 1H), 11.3 (s, 1H).

Intermediate 47 3-Chloro-4-fluoro-N,2-dihydroxybenzamide

Hydroxylamine hydrochloride (43.3 g, 0.62 mol) and KOH pellets (73.2 g,1.30 mol) were added sequentially to a solution of Intermediate 46 (58.0g, 0.28 mol) in methanol (580 mL) at 0° C., and the mixture was refluxedfor 16 hours. The reaction mixture was cooled to 10° C. and the pH ofthe solution was adjusted to 2 by addition of an ice-bath cooledsolution of 1.5N HCl (3.0 L) precipitating white solids. The solids werefiltered and dried well under vacuum. The solids were then dissolved inethyl acetate (500 mL), which was washed with 1.5N hydrochloric acid(200 mL), brine solution (200 mL) and dried over Na₂SO₄. Removal ofsolvent afforded the title product as white solid. Yield: 55.0 g (94%).¹H NMR (300 MHz, DMSO-d₆) δ: 7.0 (t, 1H), 7.7 (dt, 1H), 9.6 (br s, 1H),11.9 (s, 1H), 13.9 (s, 1H). MS (ES) MH⁺: 206 for C₇H₅ClFNO₃.

Intermediate 48 7-Chloro-6-fluorobenzo[d]isoxazol-3(2H)-one

Carbonyl diimidazole (86.75 g, 0.54 mol) in dry tetrahydrofuran (100 mL)was added drop wise to a stirred solution of Intermediate 47 (55.0 g,0.27 mol) in dry tetrahydrofuran (550 mL) at 70° C. over an hour, andthe reaction mixture was stirred at the same temperature for anadditional hour. Solvents were removed under vacuum, and the semi-solidobtained was stirred vigorously with ice-cooled 2N hydrochloric acid(500 mL) for 10 minutes. The white solid obtained was filtered dissolvedin ethyl acetate (500 mL), which was washed with brine solution (150 mL)and dried over Na₂SO₄. Removal of solvent afforded the title compound aswhite solid. Yield: 47.0 g (94%). ¹H NMR (300 MHz, DMSO-d₆) δ: 8.0 (t,1H), 8.4 (dd, 1H), 13.5 (br s, 1H). MS (ES) MH⁻: 186 for C₇H₃ClFNO₂.

Intermediate 49 3,7-Dichloro-6-fluorobenzo[d]isoxazole

To an ice cooled mixture of Intermediate 48 (47.0 g, 0.25 mol),phosphorous oxychloride (114.3 g, 0.75 mol) and triethylamine (25.36 g,0.25 mol) were added and the mixture was heated at 140° C. in a sealedtube for 6 hours. The reaction mass was cooled to room temperature andthen ice cooled water was added slowly with vigorous stirring. The solidobtained was filtered and washed with saturated sodium bicarbonatesolution (200 mL) and ice-cooled water. The wet solid was then dissolvedin diethyl ether (2.0 L), which was dried over Na₂SO₄. Removal ofsolvent at 35° C. afforded the title compound as pale brown solid.Yield: 32.0 g (62%). ¹H NMR (300 MHz, DMSO-d₆) δ: 7.6 (t, 1H), 7.9 (dd,1H). MS (ES) MH⁻: 206.0 for C₇H₂Cl₂FNO.

Intermediate 50 3,7-Dichloro-6-fluorobenzo[d]isoxazole-5-carbaldehyde

A solution of 1.6 M solution of n-butyllithium (194.17 mL, 0.31 mol) inhexanes was added drop wise to a solution of tetramethylpiperidine(48.26 g, 0.34 mol) in tetrahydrofuran (160 mL) at −10° C., and thesolution stirred for 40 minutes. The reaction mixture was cooled to −78°C. and into this was added Intermediate 49 (32.0 g, 0.16 mol) intetrahydrofuran (160 mL). After stirring −78° C. for 2 hours,dimethylformamide (22.69 g, 0.31 mol) was added and stirring wascontinued at −78° C. for 1 hour. The reaction was quenched by theaddition of acetic acid (46.6 g, 0.78 mol) and warmed to roomtemperature. The mixture was diluted with water and extracted with ethylacetate (2×250 mL). The combined organic layers were washed with waterand brine and then dried over anhydrous Na₂SO₄. Removal of the solventunder vacuum afforded the crude product, which was purified over asilica gel column (230-400 mesh) using a gradient of 2% ethyl acetate inpet. ether. Yield: 27.5 g (76%). ¹H NMR (400 MHz, DMSO-d₆) δ: 8.4 (d,1H), 10.2 (s, 1H). MS (ES) MH⁺: 233 for C₈H₂Cl₂FNO₂.

Intermediate 513,7-Dichloro-6-((2R,6R)-2,6-dimethylmorpholino)benzo[d]isoxazole-5-carbaldehyde

A mixture of Intermediate 50 (15 g, 64.10 mmol),(2R,6R)-2,6-dimethylmorpholine (7.38 g, 64.10 mmol), and K₂CO₃ (13.29 g,96.15 mmol) in butyronitrile (80 mL) and water (8 mL) was heated atreflux for 6 hours. The solvent was removed. The mixture was dilutedwith ethyl acetate and washed with water and brine. The combined aqueouslayers were extracted with ethyl acetate, which was washed with waterand brine. The combined ethyl acetate extracts were dried (Na₂SO₄) andconcentrated to give a pale yellow solid that is consistent with thetitle compound (21.2 g, 100%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.2 (d, 6H)3.0 (dd, 2H) 3.55 (dd, 2H) 4.1-4.2 (m, 2H) 8.1 (s, 1H) 10.3 (s, 1H). MS(ES) MH⁺: 329 for C₁₄H₁₄Cl₂N₂O₃.

Intermediate 523,7-Dichloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazole

To a solution of Intermediate 51 (21 g, 63.8 mmol) dissolved in 200 mLof toluene was added ethane-1,2-diol (15.8 g, 255 mmol) and4-methylbenzenesulfonic acid (0.55 g, 3.19 mmol). The mixture was heatedat reflux with azeotropic removal of water for 4 hours. The reaction wascooled and diluted with ether, which was washed with water, aqueousNaHCO₃, and water. Drying (MgSO₄) and removal of solvent gave a residuethat was purified on silica gel (25% ethyl acetate in hexanes) to givethe title compound (21.35 g, 90%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.2 (br.s., 3H) 1.3 (br. s., 3H) 2.7-3.2 (m, 3H) 3.5-3.75 (m, 1H) 3.9-4.25 (m,6H) 6.2 (s, 1H) 7.9 (s, 1H). MS (ES) MH⁺: 373 for C₁₆H₁₈Cl₂N₂O₄.

The following 3 Intermediates were prepared from the indicated startingmaterials using a method similar to the one described for the synthesisof Intermediate 42.

Intermediate 53(S)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-chlorobenzo[d]isoxazol-3-yl)-5-(methoxymethyl)oxazolidin-2-one

Starting materials: (S)-5-(methoxymethyl)oxazolidin-2-one (purchasedfrom Sanyo Co., LTD) and Intermediate 52. ¹H NMR (300 MHz, CDCl₃) δ:1.0-1.3 (m, 3H), 1.3-1.6 (m, 3H), 2.8 (d, 1H), 2.9 (s, 1H), 3.0 (s, 1H),3.05 (d, 1H), 3.2 (d, 1H) 3.4-3.5 (m, 3H), 3.7 (qd, 2H), 3.8-4.0 (m,1H), 4.1-4.35 (m, 6H), 4.9 (ddd, 1H), 6.35 (s, 1H), 8.7 (s, 1H). MS (ES)MH⁺: 468 for C₂₁H₂₆ClN₃O₇.

Intermediate 54(R)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-5-(methoxymethyl)oxazolidin-2-one

Starting material: (R)-5-(methoxymethyl)oxazolidin-2-one (purchased fromSanyoCo., LTD) and Intermediate 52. ¹H NMR (300 MHz, CDCl₃) δ: 1.2 (m,3H), 1.45 (m, 3H) 2.8 (d, 1H), 3.1 (d, 1H), 3.2-3.4 (m, 2H), 3.4-3.5 (m,3H), 3.7 (qd, 2H), 3.85 (d, 2H), 3.9-4.3 (m, 6H), 4.8-5.0 (m, 1H) 6.35(s, 1H) 8.7 (s, 1H). MS (ES) MH⁺: 468 for C₂₁H₂₆FN₃O₇.

Intermediate 55(R)-3-(7-Chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)-5-methyloxazolidin-2-one

Starting material: (R)-5-methyloxazolidin-2-one (synthesized accordingto the procedure described in Chouhan, G.; Alper, H. J. Org. Chem.(2009), 74(16), 6181-6189) and Intermediate 52. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.1 (s, 3H) 1.3 (s, 3H) 1.5 (d, 3H) 2.7-3.2 (m, 3H) 3.5-4.3(m, 9H) 4.9-5.2 (m, 1H) 6.2 (s, 1H) 8.6 (s, 1H). MS (ES) MH⁺: 438 forC₂₀H₂₄ClN₃O₆.

Intermediate 56 and 57(4S,5R)-3-[6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl]-4,5-dimethyl-oxazolidin-2-oneand(4R,5S)-3-[6-[(2R,6R)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl]-4,5-dimethyl-oxazolidin-2-one

A suspension of NaH in 10 mL dimethylformamide was added slowly to asolution of 4,5-dimethyloxazolidin-2-one (2.7 g, 18.8 mmol, synthesizedaccording to the procedure described in Chouchan, Gagan; C. J.O.C.,2009, 74, pg 6181) in 50 mL of dimethylformamide at room temperature.After 10 minutes stirring, Intermediate 11 (6.7 g, 18.8 mmol) was addedand the mixture was heated in the microwave at 100° C. for one hour. Theresulting mixture was cooled and poured into ice cold aqueous NH₄Cl, andextracted with ethyl acetate. The organic layer was washed with water,brine, and dried (Na₂SO₄). After concentration, the residue was purifiedon a silica gel column (elution with 0-5% methanol in CHCl₃) to give asolid as a mixture of diasteroemers. The diastereomers were separated bychiral HPLC using Chiralpak IC (250×4.6 mm) column(hexane:methanol:ethanol (70:15:15) 1.0 ml/min) to afford 2 components,Intermediate 56 as the first eluting isomer and Intermediate 57 as thesecond eluting isomer.

Intermediate 56 was the first eluting isomer. Yield: 840 mg (10%). ¹HNMR (300 MHz, DMSO-d₆) δ: 1.2 (d, 6H), 1.3 (d, 3H), 1.4 (d, 3H), 2.9 (s,2H), 3.2 (d, 2H), 3.9-4.2 (m, 6H), 4.7 (s, 1H), 5.1 (s, 1H), 6.2 (s,1H), 8.3 (s, 1H). MS (ES) MH⁺: 436 for C₂₁H₂₆ClN₃O₆.

Intermediate 57 was the second eluting isomer. Yield: 920 mg (11%). ¹HNMR (300 MHz, DMSO-d₆) δ: 1.2 (d, 6H), 1.3 (d, 3H), 1.4 (d, 3H), 2.9(dd, 2H), 3.2 (d, 2H), 3.9-4.2 (m, 6H), 4.5-4.9 (m, 1H), 4.9-5.2 (m,1H), 6.2 (s, 1H), 8.3 (s, 1H). MS (ES) MH⁺: 436 for C₂₁H₂₆ClN₃O₆.

Intermediate 58(S)-2-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-ylamino)pent-4-en-1-ol

Intermediate 58 was prepared from Intermediate 16 and(S)-2-aminopent-4-en-1-ol using the method described for the synthesisof Intermediate 17. ¹H NMR (300 MHz, CDCl₃) δ: 1.6 (br. s, 1H), 2.5 (t,2H), 3.7-4.0 (m, 3H), 4.0-4.35 (m, 4H), 4.5 (d, 1H), 5.0-5.3 (m, 2H),5.7-6.0 (m, 1H), 6.1 (s, 1H), 7.5 (dd, 1H). MS (ES) MH⁺: 327 forC₁₅H₁₆F₂N₂O₄.

Intermediate 59(S)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-allyloxazolidin-2-one

Intermediate 59 was prepared from Intermediate 58 using the methoddescribed for the synthesis of Intermediate 18. ¹H NMR (300 MHz, CDCl₃)δ: 2.5-2.7 (m, 1H), 2.7-2.9 (m, 1H), 4.0-4.3 (m, 4H), 4.4 (dd, 1H), 4.6(t, 1H), 4.7-4.9 (m, 1H), 5.1-5.3 (m, 2H), 5.6-5.9 (m, 1H), 6.1 (s, 1H),8.4 (dd, 1H). MS (ES) MH⁺: 353 for C₁₆H₁₄F₂N₂O₅.

Intermediate 60(S)-3-(4-Allyl-2-oxooxazolidin-3-yl)-6,7-difluorobenzo[d]isoxazole-5-carbaldehyde

Intermediate 60 was prepared from Intermediate 59 using the methoddescribed for the synthesis of Intermediate 19. MS (ES) MH⁺: 309 forC₁₄H₁₀F₂N₂O₄.

Intermediate 613-((S)-4-Allyl-2-oxooxazolidin-3-yl)-6-((2R,6R)-2,6-dimethylmorpholino)-7-fluorobenzo[d]isoxazole-5-carbaldehyde

Intermediate 61 was prepared from Intermediate 60 using the methoddescribed for the synthesis of Intermediate 20. ¹H NMR (300 MHz, CDCl₃)δ: 1.2-1.4 (m, 6H), 2.5-2.7 (m, 1H), 2.7-2.9 (m, 1H), 2.9-3.1 (m, 2H),3.4 (dt, 2H), 3.9-4.3 (m, 2H), 4.3-4.5 (m, 1H), 4.5-4.8 (m, 2H), 5.0-5.4(m, 2H), 5.5-5.9 (m, 1H), 8.7 (s, 1H), 10.4 (s, 1H). MS (ES) MH⁺: 404for C₂₀H₂₂FN₃O₅.

Intermediate 622-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-ylamino)-2-(tetrahydro-2H-pyran-4-yl)ethanol

Intermediate 62 was prepared from Intermediate 16 and4-(tetrahydro-2H-pyran-4-yl)oxazolidin-2-one (purchased from Pharmacore,Inc.) using the method described for the synthesis of Intermediate 17.MS (ES) MH⁺: 371 for C₁₇H₂₀F₂N₂O₅.

Intermediate 633-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(tetrahydro-2H-pyran-4-yl)oxazolidin-2-one

Intermediate 63 was prepared from Intermediate 62 using the methoddescribed for the synthesis of Intermediate 18. ¹H NMR (300 MHz, CDCl₃)δ: 0.7-1.0 (m, 2H), 1.4-1.6 (m, 5H), 2.6 (d, 1H), 3.15-3.5 (m, 2H),3.9-4.2 (m, 6H), 4.35-4.7 (m, 3H), 5.1-5.5 (m, 2H), 6.1 (s, 1H), 8.4(dd, 1H). MS (ES) MH⁺: 397 for C₁₈H₁₈F₂N₂O₆.

Intermediate 646,7-Difluoro-3-(2-oxo-4-(tetrahydro-2H-pyran-4-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 64 was prepared from Intermediate 63 using the methoddescribed for the synthesis of Intermediate 19. MS (ES) MH⁺: 353 forC₁₆H₁₄F₂N₂O₅.

Intermediate 656-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((2-oxo-4-(tetrahydro-2H-pyran-4-yl)-2-oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 65 was prepared from Intermediate 64 using the methoddescribed for the synthesis of Intermediate 20. MS (ES) MH⁺: 448 forC₂₂H₂₆FN₃O₆.

Intermediate 66 (S)-4-(3-Hydroxypropyl)oxazolidin-2-one

NaH (0.365 g, 9.12 mmol, 60% dispersion) was added in portions to anice-bath cooled mixture of (S)-tert-butyl1,5-dihydroxypentan-2-ylcarbamate (1 g, 4.56 mmol) dissolved in 10 mL oftetrahydrofuran. The mixture was warmed to 60° C. for 2.5 hours. Aftercooling to room temperature, the solution was acidified with 10% HCl andconcentrated. The residue was diluted with methanol and any insolublematerial was filtered off. The filtrate was concentrated to give crudeoxazolidinone and used in the next step without any furtherpurification. ¹H NMR (300 MHz, DMSO-d₆) δ: 1.1-1.2 (m, 3H) 3.4 (d, 2H)3.5 (q, 2H) 3.8-4.0 (m, 1H) 4.0-4.1 (m, 1H) 4.2-4.4 (m, 1H) 4.6-4.7 (m,2H) 7.7 (br. s, 1H).

Intermediate 67(S)-4-(3-(tert-Butyldiphenylsilyloxy)propyl)oxazolidin-2-one

Intermediate 67 was prepared from Intermediate 66 using the methodsimilar to synthesis of Intermediate 41. ¹H NMR (300 MHz, DMSO-d₆) δ:1.0 (s, 9H) 1.45-1.7 (m, 4H) 3.6-3.8 (m, 3H) 3.9 (dd, 1H) 4.3 (t, 1H)7.4-7.5 (m, 6H) 7.6-7.7 (m, 4H) 7.7 (s, 1H).

Intermediate 68(S)-4-(3-(tert-Butyldiphenylsilyloxy)propyl)-3-(6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)oxazolidin-2-one

Intermediate 68 was prepared from Intermediate 67 and Intermediate 11using the method similar to the one described for the synthesis ofIntermediate 42. MS (ES) MH⁺: 704 for C₃₈H₄₆FN₃O₇Si.

Intermediate 69(S)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-4-(3-hydroxypropyl)oxazolidin-2-one

Intermediate 69 was prepared from Intermediate 68 using the methoddescribed for the synthesis of Intermediate 43. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.2 (d, 5H) 1.3-1.5 (m, 2H) 1.7-2.0 (m, 2H) 2.9 (dd, 2H)3.2-3.4 (m. 4H) 3.95-4.1 (m, 6H) 4.3-4.5 (m, 2H) 4.6-4.8 (m, 2H) 6.2 (s,1H) 8.25 (s, 1H). MS (ES) MH⁺: 466 for C₂₂H₂₈FN₃O₇.

Intermediate 70(S)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-4-(3-fluoropropyl)oxazolidin-2-one

A solution of bis(2-methoxyethyl)amino-sulfur trifluoride (0.149 ml, 50%in tetrahydrofuran, 0.40 mmol) was added to a ice-bath cooled solutionof Intermediate 69 (125 mg, 0.27 mmol) in 10 mL CH₂Cl₂. The solution waswarmed to room temperature with stirring for 18 hours. After quenchingwith aqueous NaHCO₃, the mixture was extracted with CH₂Cl₂. Solvent wasremoved from the organic extract, and the residue was chromatographed onsilica gel (50% ethyl acetate in hexanes) to afford 83 mg (66% yield) ofthe title compound. ¹H NMR (300 MHz, DMSO-d₆) δ: 1.2 (d, 6H) 1.5-2.1 (m,4H) 2.9 (dd, 2H) 3.2-3.3 (m, 2H) 3.9-4.1 (m, 6H) 4.3-4.6 (m, 3H) 4.6-4.8(m, 2H) 6.2 (s, 1H) 8.25 (s, 1H). MS (ES) MH⁺: 468 for C₂₂H₂₇F₂N₃O₆.

Intermediate 71N-(1,4-Dihydroxybutan-2-yl)-5-(1,3-dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxybenzimidamide

Intermediate 16 (2.07 g, 7.34 mmol) and (S)-2-aminobutane-1,4-diol (1.3g, 9.18 mmol) were stirred in 50 mL dimethylformamide while cooling withan ice water bath. Triethylamine (7.68 mL, 55.09 mmol) was slowly addedover ˜10 minutes, and the reaction was allowed to warm to roomtemperature with stirring for 18 hours. The solvent was removed, and theresidue was dissolved in 4 mL of water and 5 mL of ethyl acetate. Thethick solution was filtered through a silica gel tube (10 mL capacity)with elution with ethyl acetate. The eluent was concentrated to afford3.45 g (100% yield). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.4-1.7 (m, 2H) 3.3(t, 2H) 3.3-3.5 (m, 3H) 3.9-4.1 (m, 6H) 4.3 (t, 1H) 4.6 (t, 1H) 5.7 (d,1H) 5.9-6.1 (m, 1H) 7.3 (td, 1H) 9.9 (s, 1H). MS (ES) MH⁺: 351 forC₁₄H₁₇F₃N₂O₅.

Intermediate 72(S)-2-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-ylamino)butane-1,4-diol

A mixture of Intermediate 71 (3.2 g, 9.14 mmol) and CsCO₃ (5.95 g, 18.27mmol) was dissolved in dimethylformamide (50 mL) was stirred at roomtemperature over night. The solution was decanted away from the solidsalts and filtered. The solids were washed 3× with ether and filtered.The combined filtrates were concentrated and the residue was partitionedbetween water and ethyl acetate. The ethyl acetate was separated and theaqueous layer was extracted 3 times with ethyl acetate. The organiclayers were washed 3 times with saturated aqueous NaCl, dried over MgSO₄and concentrated to give an oil. The oil was purified on silica gelcolumn using a gradient of CH₂Cl₂ to 10% CH₂Cl₂ in ethyl acetate toafford the title compound. Yield 1.0 g, 33%. ¹H NMR (300 MHz, DMSO-d₆)δ: 1.6-1.9 (m, 2H) 3.4-3.6 (m, 4H) 3.7 (td, 1H) 3.9-4.2 (m, 4H) 4.4 (t,1H) 4.6-4.8 (m, 1H) 5.7-5.8 (m, 1H) 6.1 (s, 1H) 7.05 (d, 1H) 8.0 (dd,1H). MS (ES) MH⁺: 331 for C₁₄H₁₆F₂N₂O₅.

Intermediate 73(S)-6,7-Difluoro-3-(4-(2-hydroxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 72 (220 mg, 0.67 mmol) and carbonyl diimidazole (412 mg,2.54 mmol) were dissolved in dimethylformamide (20 mL).Dimethylaminopyridine (31 mg, 0.25 mmol) was added and the reaction wasstirred at 60° C. for 2 hours. After cooling to room temperature, the 5mL of aqueous 1N HCl was added and the reaction mixture heated to 60° C.for 4 hours. Then, 2 mL of 6N HCl was added, and the reaction mixturewas stirred at 60° C. for 2 hours. The reaction mixture was concentratedand the residue was extracted 3 times with ethyl acetate. The organiclayers were washed with brine, dried over MgSO₄ and concentrated to givean oil. The residue was purified on a silica gel column using a gradientof hexanes to ethyl acetate to give the 100 mg (48% yield) of the titlecompound. ¹H NMR (300 MHz, DMSO-d₆) δ: 1.9 (m, 1H), 2.2 (m, 1H) 3.5 (q,2H), 4.5-4.6 (m, 1H), 4.6-4.7 (m, 2H), 4.7-4.8 (m, 2H), 8.7 (dd, 1H),10.2 (s, 1H). MS (ES) MH⁺: 313 for C₁₃H₁₀F₂N₂O₅.

Intermediate 746-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((S)-4-(2-hydroxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

A solution of Intermediate 73 (100 mg, 0.32 mmol), diisopropylethylamine(225 μL, 1.29 mmol) and (2R,6R)-2,6-dimethylmorpholine (44 μl, 0.35mmol) in 5 mL of acetonitrile was heated at 80° C. for 18 hours. Thereaction mixture was diluted with water and extracted 3 times with ethylacetate. The organic layers were washed twice with brine, dried overMgSO₄ and concentrated to give an oil. The residue was purified on asilica gel column using a gradient of hexanes to ethyl acetate to affordthe title compound (60 mg, 0.147 mmol, 46.0% yield). ¹H NMR (300 MHz,CDCl₃) δ: 1.3-1.4 (m, 6H), 1.9-2.1 (m, 1H), 2.3-2.5 (m, 1H), 3.0 (ddd,2H), 3.4 (dt, 2H), 3.7-3.9 (m, 2H), 4.2-4.3 (m, 2H), 4.5-4.5 (m, 1H),4.7-4.9 (m, 2H), 8.7 (d, 1H), 10.4 (s, 1H). MS (ES) MH⁺: 408 forC₁₉H₂₂FN₃O₆.

Intermediate 75(S)-5-((tert-Butyldiphenylsilyloxy)methyl)-3-(7-chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)oxazolidin-2-one

Intermediate 75 was prepared from Intermediates 41 and 52 using themethod described for the synthesis of Intermediate 32. MS (ES) MH⁺: 693for C₃₆H₄₂ClN₃O₇Si.

Intermediate 76(S)-3-(7-Chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)-5-(hydroxymethyl)oxazolidin-2-one

Intermediate 76 was prepared from Intermediate 75 using the methoddescribed for the synthesis of Intermediate 43. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.1 (br. s, 3H) 1.3 (br. s, 3H) 2.7-2.9 (m, 1H) 3.0-3.2 (m,2H) 3.6-3.8 (m, 3H) 3.9-4.2 (m, 8H) 4.8-5.0 (m, 1H) 5.3 (t, 1H) 6.2 (s,1H) 8.6 (s, 1H). MS (ES) MH⁺: 454 for C₂₀H₂₄ClN₃O₇.

Intermediate 77(S)-3-(7-Chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)-5-(fluoromethyl)oxazolidin-2-one

Intermediate 77 was prepared from Intermediate 76 using a method similarto the one described for the synthesis of Intermediate 70. ¹H NMR (300MHz, DMSO-d₆) δ: 1.1 (br s, 3H) 1.3 (br s, 3H) 2.65-2.9 (m, 1H) 2.9-3.2(m, 2H) 3.5-3.7 (m, 1H) 3.8-4.2 (m, 7H) 4.2-4.35 (m, 1H) 4.6-4.9 (m, 2H)5.05-5.3 (m, 1H) 6.2 (s, 1H) 8.6 (s, 1H). MS (ES) MH⁺: 456 forC₂₀H₂₃ClFN₃O₆.

Intermediate 78(S)-4-(3-(tert-Butyldiphenylsilyloxy)propyl)-3-(7-chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)oxazolidin-2-one

Intermediate 78 was prepared from Intermediate 67 and Intermediate 52using a method similar to the one described for the synthesis ofIntermediate 42. ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9 (s, 9H) 1.1 (br. s.,3H) 1.3 (br. s., 3H) 1.4-1.65 (m, 2H) 1.85-2.0 (m, 2H) 2.7-3.1 (m, 3H)3.5-3.7 (m, 3H) 3.95-4.2 (m, 6H) 4.3-4.4 (m, 1H) 4.6-4.8 (m, 2H) 6.2 (s,1H) 7.3-7.5 (m, 6H) 7.5-7.6 (m, 4H) 8.4 (s, 1H). MS (ES) MH⁺: 720 forC₃₈H₄₆1N₃O₇Si.

Intermediate 79(S)-3-(7-Chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)-4-(3-hydroxypropyl)oxazolidin-2-one

Intermediate 79 was prepared from Intermediate 78 using the methoddescribed for the synthesis of Intermediate 43. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.1 (br. s, 3H) 1.25-1.5 (m, 5H) 1.7-2.0 (m, 2H) 2.7-2.9 (m,1H) 3.0-3.2 (m, 2H) 3.3-3.45 (m, 2H) 3.5-3.7 (m, 1H) 3.9-4.15 (m, 6H)4.3-4.5 (m, 2H) 4.6-4.8 (m, 2H) 6.2 (s, 1H) 8.4 (s, 1H). MS (ES) MH⁺:482 for C₂₂H₂₈ClN₃O₇.

Intermediate 80(S)-3-(7-Chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)-4-(3-fluoropropyl)oxazolidin-2-one

Intermediate 80 was prepared from Intermediate 79 using the methoddescribed for the synthesis of Intermediate 70. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.1 (br. s, 3H) 1.3 (br. s, 3H) 1.5-2.0 (m, 4H) 2.7-2.9 (m,1H) 3.0-3.1 (m, 2H) 3.5-3.7 (m, 1H) 3.9-4.15 (m, 6H) 4.3-4.6 (m, 3H)4.65-4.8 (m, 2H) 6.2 (s, 1H) 8.4 (s, 1H). MS (ES) MH⁺: 484 forC₂₂H₂₇ClFN₃O₆.

Intermediate 81(S)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-5-(methoxymethyl)oxazolidin-2-one

Intermediate 81 was prepared from Intermediate 11 and(S)-5-(methoxymethyl)oxazolidin-2-one (purchased from Daisco Co., LTD)using the method described for Intermediate 12. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.2 (d, 6H), 2.9 (dd, 2H), 3.2-3.3 (m, 2H), 3.3 (s, 3H),3.6-4.3 (m, 9H), 4.9-5.2 (m, 1H), 6.2 (s, 1H), 8.4 (s, 1H). MS (ES) MH⁺:452 for C₂₁H₂₆FN₃O₇.

Intermediate 82(R)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-5-(methoxymethyl)oxazolidin-2-one

Intermediate 82 was prepared from (R)-5-(methoxymethyl)oxazolidin-2-one(purchased from Daisco Co., LTD) and Intermediate 11 using the methoddescribed for the synthesis of Intermediate 12. ¹H NMR (300 MHz,DMSO-d₆) δ: 1.2 (d, 6H) 2.9 (dd, 4.8 Hz, 2H) 3.1-3.3 (m, 2H) 3.3 (s, 3H)3.6-4.3 (m, 9H) 4.9-5.1 (m, 1H) 6.2 (s, 1H) 8.4 (s, 1H). MS (ES) MH⁺:452 for C₂₁H₂₆FN₃O₇.

Intermediate 83 (5R)-5-(Hydroxymethyl)-1,3-oxazolidin-2-one

To a stirred solution of 3-amino-1,2-propanediol (5.07 g, 55.7 mmol) inwater (60 mL), sodium bicarbonate (20.70 g, 195.3 mmol) followed bytriphosgene (4.70 g, 15.8 mmol) portion wise and the mixture was stirredat the room temperature for 16 hours. The reaction mixture wasneutralized with 1.5N hydrochloric acid carefully and the water wasremoved under vacuum to and the residue was dissolved in ethanol (250mL) and filtered through celite. The residue was washed with ethanol(250 mL) and the solvents of the filtrates were removed under vacuum.The solid thus obtained was purified by silica gel column chromatographyusing a gradient of methanol in ethyl acetate. Yield: 3.30 (51%) ¹H NMR(300 MHz, DMSO-d₆) δ: 3.18-3.30 (m, 1H), 3.45-3.56 (m, 3H), 4.47-4.55(m, 1H), 4.05 (t, 1H), 7.39 (s, 1H).

Intermediate 84(5R)-5-[(Tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 83 (5.0 g, 42.7 mmol) indichloromethane (50 mL), pyridinium p-toluenesulfonate (1.07 g, 4.27mmol) and 3,4-dihydropyran (5.84 mL, 64.1 mmol) were added and themixture was stirred at the room temperature for 16 hours. The reactionmixture was quenched with brine solution (25 mL) and extracted withdichloromethane (3×25 mL). The combined organic layers were dried oversodium sulfate and the solvents were removed under vacuum. The crudeproduct obtained was purified by silica gel flash column chromatographyusing 50% ethyl acetate in hexane. Yield: 5.0 g (58%) ¹H NMR (300 MHz,DMSO-d₆): δ 1.45-1.49 (m, 4H), 1.57-1.73 (m, 2H), 3.12-3.28 (m, 1H),3.45-3.55 (m, 3H), 3.67-3.75 (m, 2H), 4.62-4.63 (m, 1H), 4.70-4.72 (m,1H), 7.50 (s, 1H). MS (ELSD) MH⁺: 202.2 for C₉H₁₅FNO₄.

Intermediate 85(5R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-[(tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-oxazolidin-2-one

To a stirred solution of sodium hydride (0.61 g, 25.5 mmol) in dimethylformamide (10 mL), a solution of Intermediate 84 (2.57 g, 12.7 mmol) indimethyl formamide (20 mL) was added slowly at 0° C. over a period of 10minutes. The mixture was stirred at the room temperature for 30 minutesand a solution of Intermediate 11 (4.55 g, 12.7 mmol) in dimethylformamide (20 mL) was added at the same temperature and the mixture washeated at 60° C. for 2 hours. The reaction was quenched with saturatedammonium chloride solution (10 mL), extracted with ethyl acetate (3×50mL). The combined organic layers were dried over anhydrous sodiumsulfate and the solvents were removed under vacuum. The crude productwas purified by silica gel column chromatography using a gradient ofethyl acetate in hexane. Yield: 2.0 g (30%). ¹H NMR (400 MHz, DMSO-d₆)δ: 1.16 (d, 6H), 1.39-1.48 (m, 5H), 2.85-2.90 (m, 2H), 3.18-3.21 (m,4H), 3.58-3.83 (m, 2H), 3.93-3.99 (m, 2H), 4.04-4.07 (m, 5H), 4.46-4.58(m, 2H), 4.67-4.76 (m, 2H), 6.15 (s, 1H), 8.25 (d, 1H). MS (ES) MH⁺:522.2 for C₂₅H₃₂FN₃O₈.

Intermediate 86(5R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-(hydroxymethyl)-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 85 (2.6 g, 4.99 mmol) in toluene(20 mL), ethylene glycol (2.0 mL) followed by pyridinium p-toluenesulfonate (0.23 g, 0.99 mmol) and the mixture was heated at 110° C. for1.5 hours. The reaction mixture was quenched with saturated sodiumbicarbonate solution (10 mL) and extracted with ethyl acetate (3×25 mL).The organic layers were washed with brine, dried over sodium sulfate andthe solvents were removed under vacuum. The crude product was purifiedby flash column silica gel chromatography using 30% ethyl acetate inhexane. Yield: 1.40 g (66%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.20 (d, 6H),2.88-2.92 (m, 2H), 3.21-3.23 (m, 2H), 3.61-3.65 (m, 1H), 3.72-3.77 (m,1H), 3.93-4.01 (m, 3H), 4.04-4.10 (m, 4H), 4.19 (t, 1H), 4.88-4.92 (m,1H), 5.30 (t, 1H), 6.18 (s, 1H), 8.45 (s, 1H). MS (ES) MH⁺: 438.4 forC₂₀H₂₄FN₃O₇.

Intermediate 87(5R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-(fluoromethyl)-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 86 (0.10 g, 0.21 mmol) intetrahydrofuran (3 mL), diethylaminosulfur trifluoride (0.17 g, 1.06mmol) was added at −78° C. and the mixture was stirred at the sametemperature for another hour and then it was stirred at the roomtemperature for 2 hours. Methanol (1 mL) was added to the reactionmixture and the volatiles were removed under vacuum. The residue wasdissolved in ethyl acetate (15 mL) and washed with saturated sodiumbicarbonate (5 mL), water (10 mL) and finally with brine solution. Theorganic layer was dried over sodium sulfate and the solvent was removedunder vacuum. The solid obtained was pure enough and it was taken to thenext step without further purification. Yield: 0.05 g (55%). MS (ES)MH⁺: 440.4 for C₂₀H₂₃F₂N₃O₆

Intermediate 88(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-ethenyl-1,3-oxazolidin-2-one

To a stirred suspension of sodium hydride (0.71 g, 17.6 mmol) indimethyl formamide (10 mL), a solution of(4S)-4-ethenyl-1,3-oxazolidin-2-one (prepared according to theliterature procedure Chem. Eur. J. 2006, 12, 6607-6620, 2.0 g, and 17.6mmol) in dimethylformamide (10 mL) was added slowly at 0° C. over aperiod of 10 minutes. The mixture was stirred at the room temperaturefor 30 minutes and a solution of Intermediate 11 (3.1 g, 8.84 mmol) indimethylformamide (10 mL) was added at the same temperature. Thismixture was heated at 80° C. for 12 hours and poured into ice-cooledwater and extracted with ethyl acetate (3×25 mL). The organic layerswere dried over anhydrous sodium sulfate and the solvents were removedunder vacuum. The crude product was purified by silica gel columnchromatography using a gradient of ethyl acetate in pet. ether. Yield:0.70 g (19%). MS (ES) MH⁺: 434.3 for C₂₁H₂₄FN₃O₆.

Intermediate 89(5R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-[(E)-(hydroxyimino)methyl]-1,3-oxazolidin-2-one

To a solution of dimethyl sufoxide (0.22 g, 2.74 mmol), indichloromethane (3 mL), oxalyl chloride (0.18 g, 1.37 mmol) was added at−80° C. under nitrogen atmosphere and the mixture was stirred at thattemperature for 30 minutes. To this, a solution of Intermediate 86 (0.4g, 0.92 mmol) in dichloromethane (3 mL) was added drop wise at the sametemperature and the reaction mixture was stirred at this temperature for3 hours before adding triethylamine (0.46 g, 4.50 mmol) at the sametemperature. Then it was brought to the 0° C. where it was stirred for1.5 hours and water was added to it (5 mL) and diluted withdichloromethane (5 mL). The organic layers were extracted and dried oversodium sulfate and the solvent was removed under vacuum at the roomtemperature. The crude material (0.36 g) was dissolved in absoluteethanol (10 mL) and hydroxylamine hydrochloride (0.9 g, 1.20 mmol) wasadded followed by sodium acetate (0.08 g, 1.20 mmol) and the mixture wasrefluxed for 3 hours. Volatiles were removed and the residue was pouredinto water and filtered and the precipitates were washed with water (25mL) and dried. The crude product was purified by silica gel flash columnchromatography using a gradient of ethyl acetate in pet. ether. Thecompound was obtained as an undefined mixture of E & Z isomers (1:2ratio by ¹H NMR). Yield: 0.13 g (35%) ¹HNMR (400 MHz, DMSO-d₆) δ: 1.24(br s, 6H), 2.89-2.93 (m, 2H), 3.21-3.24 (m, 2H), 3.95-4.00 (m, 2H),4.02-4.11 (m, 4H), 4.20 (t, 1H), 4.34 &4.44 (t, 1H), 5.43 & 5.82 (quin,1H), 6.18 (s, 1H), 7.21 & 7.65 (d, 1H), 8.41-8.42 (m, 1H), 11.58 & 11.78(s, 1H). MS (ES) MH⁺: 451.4 for C₂₀H₂₃FN₄O₇.

Intermediate 90(4R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-2-oxo-1,3-oxazolidine-4-carbaldehyde

To a solution of Intermediate 88 (0.4 g, 0.92 mmol) in tetrahydrofuran(4 mL) and water (4 mL), N-methyl morpholine-N-oxide (0.22 g, 1.84 mmol)and 2 wt % in solution osmium tetroxide in t-butanol (0.02 g, 0.05 mmol)were added and the mixture was stirred at the room temperature for 3hours. To this solution, benzene iodosodiacetate (0.75 g, 2.3 mmol) wasadded and it was stirred for 16 hours. The reaction mass was extractedwith ethyl acetate (3×20 mL), the combined organic layers were washedwith water (15 mL), dried over sodium sulfate and the solvents wereremoved under vacuum. The solid was taken to the next step withoutfurther purification. Yield: 0.40 g (crude). ¹HNMR (400 MHz, DMSO-d₆) δ:1.24 (d, 6H), 2.89-2.96 (m, 2H), 3.31-3.50 (m, 2H), 4.02-4.17 (m, 8H),4.56-4.74 (m, 1H), 6.32 (s, 1H), 8.52 (s, 1H), 9.90 (s, 1H). MS (ES)MH⁺: 451.4 for C₂₀H₂₂FN₃O₇.

Intermediate 91(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-[(E)-(hydroxyimino)methyl]-1,3-oxazolidin-2-one

To a solution of Intermediate 90 (0.4 g, 0.92 mmol) in pyridine (5 mL)and methanol (5 mL), hydroxylamine hydrochloride (0.08 g, 1.1 mmol) wasadded and the mixture was heated at 95° C. for 30 minutes. The volatileswere removed under vacuum and the crude product was dissolved in ethylacetate (30 mL), washed with water (2×15 mL) and brine (15 mL), driedover sodium sulfate. Removal of solvent under vacuum afforded the titlecompound as 40:60 mixture of E/Z isomer which was further purified bywashing with hexane (25 mL). Yield: 0.37 g (90%) ¹HNMR (400 MHz,DMSO-d₆) δ: 1.24 (d, 6H), 2.89-2.91 (m, 2H), 3.19-3.22 (m, 2H),3.96-4.07 (m, 6H), 4.31 & 4.52 (dd, 1H), 4.75 & 4.87 (t, 1H), 5.25-5.29& 5.51-5.61 (m, 1H), 6.16 & 6.17 (s, 1H), 7.12 & 7.53 (d, 1H), 8.27 &8.37 (s, 1H), 11.24 & 11.55 (s, 1H). MS (ES) MH⁺: 451.4 for C₂₀H₂₃FN₄O₇.

Intermediate 92(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-2-oxo-1,3-oxazolidine-4-carbonitrile

A solution of Intermediate 91 (0.18 g, 0.4 mmol) intrichloroacetonitrile (10 mL) was heated at 95° C. for an hour. Thevolatiles were evaporated and the crude product was recrystallised usingethyl acetate and hexane. Yield: 0.09 g (53%). ¹HNMR (400 MHz, DMSO-d₆)δ: 1.21 (d, 6H), 2.87-2.93 (m, 2H), 3.23 (d, 2H), 3.94-4.04 (m, 6H),4.85 (d, 2H), 5.64 (dd, 1H), 6.17 (s, 1H), 8.32 (s, 1H). MS (ES) MH⁺:436.4 for C₂₀H₂₃FN₄O₇.

Intermediate 93(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-[(E)-(methoxyimino)methyl]-1,3-oxazolidin-2-one

Intermediate 93 was prepared from Intermediate 90 and O-methylhydroxylamine hydrochloride using the method described for the synthesisof Intermediate 91. ¹HNMR (400 MHz, DMSO-d₆) δ: 1.24 (d, 6H), 2.89-2.91(m, 2H), 3.19-3.22 (m, 2H), 3.32 & 3.72 (s, 3H), 3.96-4.09 (m, 6H), 4.31& 4.52 (dd, 1H), 4.75 & 4.87 (t, 1H), 5.25-5.29 & 5.51-5.61 (m, 1H),6.17 (s, 1H), 7.25 & 7.66 (d, 1H), 8.27 & 8.36 (s, 1H). MS (ES) MH⁺:465.4 for C₂₁H₂₅FN₄O₇.

Intermediate 94(5R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-5-[(E)-(methoxyimino)methyl]-1,3-oxazolidin-2-one

Intermediate 94 was prepared from Intermediate 85 and O-methylhydroxylamine hydrochloride using the method described for the synthesisof Intermediate 86. The compound was obtained as an undefined mixture ofE & Z isomers (1:2.3). Yield: 0.13 (30%). ¹HNMR (400 MHz, DMSO-d₆) δ:1.24 (d, 6H), 2.86-2.91 (m, 2H), 3.19-3.25 (m, 2H), 3.76 & 3.83 (s, 3H),3.91-3.99 (m, 2H), 4.00-4.07 (m, 4H), 4.14-4.19 (m, 1H), 4.32-4.44 (m,1H), 5.25-5.39-5.46 & 5.75-5.76 (m, 1H), 6.16 (s, 1H), 7.31 & 7.75 (d,1H), 8.40 (s, 1H). MS (ES) MH⁺: 465.3 for C₂₁H₂₅FN₄O₇.

Intermediate 95[(5R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-2-oxo-1,3-oxazolidin-5-yl]methyl4-methylbenzenesulfonate

To a stirred solution of Intermediate 86 (2.7 g, 6.10 mmol) indichloromethane (50 mL), 4-dimethylaminopyridine (1.50 g, 12.3 mmol) wasadded at 0° C. followed by p-toluene sulfonyl chloride (1.76 g, 9.20mmol). The resulting solution was brought to the room temperature afterstirred at the same temperature for an hour where it was stirred for afurther period of an hour. The reaction mixture was washed with citricacid solution (25 mL), water (25 mL), saturated sodium bicarbonatesolution (25 mL) and again with water (2×25 mL). The organic layer wasdried over sodium sulfate and the solvents were removed under vacuum toobtained crude product which was purified by silica gel flash columnchromatography using a gradient of ethyl acetate in hexane. Yield: 3.2 g(88%) ¹H NMR (400 MHz, DMSO-d₆) δ: 1.20 (d, 6H), 2.39 (s, 3H), 2.88-2.92(m, 2H), 3.19-3.22 (m, 2H), 3.78 (dd, 1H), 3.94-3.99 (m, 2H), 4.04-4.10(m, 4H), 4.19 (t, 1H), 4.41 (d, 2H), 5.05-5.07 (m, 1H), 6.16 (s, 1H),7.45 (d, 2H), 7.77 (d, 2H), 8.38 (s, 1H). MS (ES) MH⁺: 592.4 forC₂₇H₃₀FN₃O₉S.

Intermediate 96(5R)-5-(Azidomethyl)-3-{6-[(2R,6R)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 95 (3.20 g, 5.40 mmol) indimethylformamide (30 mL) in a sealed tube, sodium azide (1.0 g, 16.20mmol) was added and the mixture was heated at 90° C. for 3 hours. Thereaction was quenched with water (15 mL) after being brought to roomtemperature and extracted with ethyl acetate (2×15 mL). The combinedorganic layers were washed with water (2×10 mL) and brine solution (10mL), dried over sodium sulfate and the solvent was removed under vacuumafforded the crude title compound, which was further purified by flashcolumn chromatography using a gradient of ethyl acetate in pet. ether toobtain the pure product as colorless viscous liquid. Yield: 2.1 g (51%).¹H NMR (400 MHz, DMSO-d₆) δ: 1.24 (d, 6H), 2.90 (dd, 2H), 3.22 (d, 2H),3.82 (d, 2H), 3.88 (dd, 1H), 3.95-4.00 (m, 2H), 4.02-4.10 (m, 4H), 4.25(t, 1H), 5.08-5.11 (m, 1H), 6.18 (s, 1H), 8.44 (s, 1H). MS (ES) MH⁺:463.4 for C₂₀H₂₃FN₆O₆.

Intermediate 97 Methyl (4R)-2-oxo-1,3-oxazolidine-4-carboxylate

To a suspension of D-serine methyl ester hydrochloride (25.0 g, 160.7mmol) in tetrahydrofuran (150 mL), a solution of triphosgene (47.68 g,160.7 mmol) in tetrahydrofuran (100 mL) was added at 0° C. and themixture was stirred at 80° C. for 2 hours. The volatiles were evaporatedunder vacuum and the residue was subjected to flash column silica gelchromatography using 5% methanol in chloroform. Yield: 17.5 g (75%). ¹HNMR (400 MHz, DMSO-d₆) δ: 3.69 (s, 3H), 4.32-4.33 (m, 1H), 4.32-4.33 (m,2H), 8.22 (s, 1H).

Intermediate 98 (4S)-4-(Hydroxymethyl)-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 97 (15.0 g, 103.4 mmol) in ethanol(100 mL), sodium borohydride (1.96 g, 51.7 mmol) was added portionwiseat 0° C. and the mixture was stirred at room temperature for 30 minutes.To this mixture, 1.5 N hydrochloric acid was added and the volatileswere removed under vacuum. Methanol (50 mL) was added to the residue,filtered through celite and the solvents were removed under vacuum. Thetitle compound was obtained as colorless oil, which was used in thefurther step without purification. Chiral HPLC data showed a mixture of91.3:8.7 enantiomers [Column: Chiralpak AD-H (250×4.6) mm 5 μm; MobilePhase: Hexane:Ethanol (85:15)]. ¹H NMR (400 MHz, DMSO-d₆) δ: 3.34-3.35(m, 2H), 3.70-3.72 (m, 1H), 4.04 (dd, 1H), 2.96 (t, 1H), 4.96 (t, 1H),7.59 (s, 1H).

Intermediate 99 [(4R)-2-Oxo-1,3-oxazolidin-4-yl]methyl4-methylbenzenesulfonate

To a stirred solution of Intermediate 98 (11.0 g, 94.0 mmol) indichloromethane (250 mL), 4-dimethylamino pyridine (22.94 g, 188.0 mmol)and p-toluene sulfonylchloride (26.88 g, 141.0 mmol) were added at 0° C.and it was stirred for an hour before bringing to the room temperature,and the reaction was stirred for an hour. The reaction mixture waswashed with 1.5N hydrochloric acid (50 mL), water (50 mL), saturatedsodium bicarbonate (50 mL) and finally with brine. The organic layer wasdried over sodium sulfate and the solvent was removed under vacuum. Thecrude product was then purified by flash column chromatography in silicagel using a gradient of ethyl acetate in pet. ether. ¹H NMR (300 MHz,DMSO-d₆) δ: 2.49 (s, 3H), 3.91-3.95 (m, 2H), 3.99-4.02 (m, 2H), 4.30 (t,1H), 7.49 (d, 2H), 7.80 (d, 2H), 7.88 (s, 1H). Yield: 12.0 g (47%).

Intermediate 100 (R)-4-((Methylthio)methyl)oxazolidin-2-one

To a stirred solution Intermediate 99 (4.00 g, 14.76 mmol) in methanol(30 mL) in a sealed tube, sodium thiomethoxide (3.12 g, 44.28 mmol) wasadded and the mixture was stirred at room temperature for 2 hours. Thevolatiles were removed under vacuum and the residue was dissolved indichloromethane (50 mL) and the organic layer was washed with water(2×25 mL), brine (25 mL) and dried over sodium sulfate. Removal of thesolvent afforded the title compound. Yield: 0.82 g (38%). ¹H NMR (300MHz, DMSO-d₆) δ: 2.08 (s, 3H), 2.59 (d, 2H), 3.93-4.03 (m, 2H), 4.37 (t,1H), 7.78 (s, 1H).

Intermediate 101(R)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-4-((methylthio)methyl)oxazolidin-2-one

To a stirred suspension of sodium hydride (0.22 g, 5.5 mmol) in dimethylformamide (5 mL), a solution of Intermediate 100 (0.82 g, and 5.5 mmol)in dimethylformamide (10 mL) was added slowly at 0° C. over a period of10 minutes. The mixture was stirred at the room temperature for 10minutes and a solution of (Intermediate 11 (1.96 g, 5.50 mmol) indimethylformamide (10 mL) was added at the same temperature. Thismixture was heated at 80° C. for 2 hours and poured into ice-cooledsaturated ammonium chloride solution (20 mL) and extracted with ethylacetate (3×20 mL). The organic layers were dried over anhydrous sodiumsulfate and the solvents were removed under vacuum. The crude productwas purified by silica gel column chromatography using a gradient ofethyl acetate in pet.ether. Yield: 0.70 g (27%). ¹H NMR (300 MHz,DMSO-d₆) δ: 1.22 (br s, 6H), 2.04 (s, 3H), 2.86-2.91 (m, 2H), 3.02-3.04(m, 2H), 3.19-3.22 (m, 2H), 3.96-4.07 (m, 6H), 4.42 (dd, 1H), 4.73 (t,1H), 4.84-4.86 (m, 1H), 6.16 (s, 1H), 8.28 (s, 1H). MS (ES) MH⁺: 468.2for C₂₁H₂₆FN₃O₆S.

Intermediate 102(R)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-4-((methylsulfonyl)methyl)oxazolidin-2-one

To a stirred solution of Intermediate 101 (0.20 g, 0.42 mmol) intetrahydrofuran (5 mL) m-chloroperbenzoic acid (0.37 g, 2.14 mmol) wasadded and the mixture was stirred at the room temperature for 2 hours.Water (2 mL) was added to the reaction mixture and extracted with ethylacetate (3×5 mL). The combined organic layers were washed with water(2×5 mL), brine (5 mL) and dried over sodium sulfate. Removal of thesolvent under vacuum afforded the title compound as pale yellow solid.Yield: 0.20 g (94%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.22 (br s, 6H),2.88-2.92 (m, 2H), 3.10 (s, 3H), 3.20-3.23 (m, 2H), 3.77-3.83 (m, 1H),3.88-3.93 (m, 1H), 3.96-4.00 (m, 2H), 4.02-4.10 (m, 4H), 4.68 (dd, 1H),4.81 (t, 1H), 5.10-5.14 (m, 1H), 6.17 (s, 1H), 8.27 (s, 1H). MS (ES)MH⁺: 500.3 for C₂₁H₂₆FN₃O₈S.

Intermediate 103 MethylN-(tert-butoxycarbonyl)-O-(tetrahydro-2H-pyran-2-yl)-L-serinate

To a stirred solution of methyl N-(tert-butoxycarbonyl)-L-serinate(prepared according to the reported procedure: Bioorg. Med. Chem. 2007,15, 2860-2867, 10.0 g, 64.27 mmol) in dichloromethane (100 mL),p-toluenesulfonic acid (0.24 g, 1.28 mmol) and 3,4-dihydro-1H-pyran (8.8mL, 96.67 mmol) were added and the mixture was stirred at the roomtemperature for 16 hours. The reaction mixture was quenched withsaturated sodium bicarbonate solution (50 mL) and extracted withdichloromethane (3×50 mL). The combined organic layers were washed withwater (2×50 mL), brine solution (50 mL) and dried over sodium sulfate.Removal of solvent under vacuum and also high vacuum to remove excess3,4-dihydro-1H-pyran. The residue was dissolved in ethyl acetate (10 mL)and pet. ether (100 mL) was added over it was stirred for 10 minutes.The solid obtained was filtered and washed with pet. ether (50 mL).Yield: 12.0 g (78%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.33-1.34 (m, 1H),1.39 (s, 9H), 1.41-1.68 (m, 6H), 3.41-3.45 (m, 1H), 3.55-3.59 (m, 1H),3.61 (s, 3H), 3.81-3.84 (m, 1H), 4.23-4.28 (m, 1H), 4.58 (br s, 1H),7.15 (d, 1H).

Intermediate 104tert-Butyl[(2R)-1-hydroxy-3-(tetrahydro-2H-pyran-2-yloxy)propan-2-yl]carbamate

To a stirred solution of Intermediate 103 (41.0 g, 135.0 mmol) intetrahydrofuran (250 mL) and methanol (125 mL), sodium borohydride(15.32 g, 405.0 mmol) was added portion wise at 0° C. and the mixturewas stirred at the room temperature for 30 minutes. The volatiles wereremoved in vacuo and the residue was taken in ethyl acetate (250 mL) andwashed with water (2×50 mL) and brine solution (50 mL). The organiclayers were dried over sodium sulfate and the solvents were removedunder vacuum. The crude product was purified by flash columnchromatography using silica gel (40% ethyl acetate in pet. ether).Yield: 35.5 g (96%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.41 (s, 9H),1.44-1.70 (m, 7H), 3.34-3.41 (m, 3H), 3.47-3.69 (m, 2H), 3.70-3.75 (m,1H), 4.53-4.61 (m, 2H), 6.46 (d, 1H).

Intermediate 105(4S)-4-[(Tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 104 (35.5 g, 129.0 mmol) intetrahydrofuran (250 mL), 1M solution of potassium t-butoxide intetrahydrofuran (258.0 mL, 258.0 mmol) was added at 0° C. and themixture was stirred at the room temperature for 30 minutes. The reactionmixture was quenched with water (50 mL) at 0° C. and extracted withethyl acetate (3×50 mL). The combined organic layers were washed withwater (50 mL), brine solution (50 mL) and dried over sodium sulfate andthe solvents were removed under vacuum. The crude product obtained waspurified by silica gel flash column chromatography using a gradient ofethyl acetate in hexane. Yield: 22.0 g (85%). ¹H NMR (400 MHz, DMSO-d₆):δ 1.38-1.51 (m, 4H), 1.59-1.62 (m, 1H), 1.73-1.75 (m, 1H), 3.35-3.37 (m,1H), 3.45-3.47 (m, 1H), 3.56-3.59 (m, 1H), 3.72-3.77 (m, 1H), 3.93 (h,1H), 4.05-4.08 (m, 1H), 4.35 (t, 1H), 4.60 (t, 1H), 7.75 (t, 1H). MS(ELSD) MH⁺: 202.2 for C₉H₁₅FNO₄.

Intermediate 106(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-[(tetrahydro-2H-pyran-2-yloxy)methyl]-1,3-oxazolidin-2-one

To a stirred solution of sodium hydride (1.41 g, 35.3 mmol) in dimethylformamide (10 mL), a solution of Intermediate 105 (7.1 g, 35.3 mmol) indimethyl formamide (50 mL) was added slowly at 0° C. over a period of 10minutes and the mixture was stirred at the room temperature for 30minutes. A solution of Intermediate 11 (12.59 g, 35.3 mmol) in dimethylformamide (50 mL) was added at the same temperature and the mixture washeated at 60° C. for 2 hours. The reaction was quenched with saturatedammonium chloride solution (10 mL), extracted with ethyl acetate (3×50mL). The combined organic layers were dried over anhydrous sodiumsulfate and the solvents were removed under vacuum. The crude productwas purified by silica gel column chromatography using a 3% methanol inchloroform. Yield: 4.3 g (23%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.18 (d,6H), 1.30-1.58 (m, 5H), 2.85-2.90 (m, 2H), 3.18-3.21 (m, 4H), 3.58-3.83(m, 2H), 3.93-3.99 (m, 2H), 4.04-4.07 (m, 5H), 4.46-4.58 (m, 2H),4.67-4.76 (m, 2H), 6.15 (s, 1H), 8.25 (d, 1H). MS (ES) MH⁺: 522.2 forC₂₅H₃₂FN₃O₈.

Intermediate 107(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(hydroxymethyl)-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 106 (3.2 g, 6.21 mmol) in toluene(30 mL), ethylene glycol (2.0 mL) followed by pyridinium p-toluenesulfonate (0.59 g, 23.6 mmol) and the mixture was heated at 110° C. for1.5 hours. The reaction mixture was quenched with saturated sodiumbicarbonate solution (10 mL) and extracted with ethyl acetate (3×25 mL).The organic layers were washed with brine, dried over sodium sulfate andthe solvents were removed under vacuum. The crude product thus obtainedwas purified by flash column silica gel chromatography using 30% ethylacetate in hexane. Chiral HPLC data shows that it was 97% de [Column:Chiralpak IC (250×4.6 mm); Mobile Phase: hexane:ethanol (80:20)]. Yield:1.63 g (60%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.09 (d, 6H), 2.83 (t, 2H),3.08 (d, 2H), 3.53-3.57 (m, 1H), 3.73-3.76 (m, 2H), 3.91-3.99 (m, 3H),4.06-4.09 (m, 2H), 4.48 (dd, 1H), 4.63-4.65 (m, 2H), 5.19 (t, 1H), 6.11(s, 1H), 8.32 (s, 1H). MS (ES) MH⁺: 438.4 for C₂₀H₂₄FN₃O₇.

Intermediate 108((R)-3-(6-((2R,6R)-2,6-Dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)-2-oxooxazolidin-4-yl)methyl4-methylbenzenesulfonate

To a stirred solution of Intermediate 107 (4.5 g, 10.29 mmol) indichloromethane (100 mL), N,N-dimethylaminopyridine (2.51 g, 20.59 mmol)and p-toluene sulfonyl chloride (2.94 g, 15.43 mmol) were added and thesolution was stirred at 0° C. for an hour before it was brought to theroom temperature where it was stirred for an additional hour. Thereaction mixture was washed with 1.5 N hydrochloric acid (50 mL), water(2×50 mL) and saturated sodium bicarbonate solution (50 mL), dried oversodium sulfate. Removal of solvent under vacuum afforded off white solidwhich was further purified by silica gel flash column chromatographyusing a gradient of ethyl acetate in hexane. Yield: 5.0 g (82%). ¹H NMR(300 MHz, DMSO-d₆) δ: 1.21 (d, 6H), 2.16 (s, 3H), 2.86-2.92 (m, 2H),3.08 (d, 2H), 3.95-4.10 (m, 6H), 4.35 (d, 1H), 4.44-4.47 (m, 1H), 4.55(d, 1H), 4.67 (t, 1H), 4.78-4.83 (m, 1H), 6.19 (s, 1H), 7.1 (d, 2H),7.54 (d, 2H), 8.29 (s, 1H). MS (ES) MH⁺: 592.6 for C₂₇H₃₀FN₃O₉S.

Intermediate 109(S)-4-(Azidomethyl)-3-(6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)oxazolidin-2-one

To a stirred solution of Intermediate 108 (1.5 g, 2.53 mmol) indimethylformamide (15 mL) in a sealed tube, sodium azide (0.99 g, 15.22mmol) was added and the mixture was heated at 90° C. for 2 hours. Thereaction was quenched with water (15 mL) after being brought to roomtemperature and extracted with ethyl acetate (2×30 mL). The combinedorganic layers were washed with water (2×10 mL) and brine solution (10mL), dried over sodium sulfate and the solvent was removed under vacuumafforded the crude title compound which was further purified by flashcolumn chromatography using a gradient of ethyl acetate in pet. ether toobtain the pure product as colorless viscous liquid. Yield: 0.85 g(73%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.20 (br s, 6H), 2.91-2.93 (m, 2H),3.21-3.23 (m, 2H), 3.70 (d, 2H), 3.98-4.15 (m, 7H), 4.71 (t, 1H),4.80-4.82 (m, 1H), 6.18 (s, 1H), 8.29 (s, 1H). MS (ES) MH⁺: 463.4 forC₂₀H₂₃FN₆O₆.

Intermediate 110 Methyl N-[(benzyloxy)carbonyl]-O-ethyl-L-serinate

To a stirred solution of (S)-1-benzyl 2-methylaziridine-1,2-dicarboxylate (prepared according to the literatureprocedure: Org. Biomol. Chem., 2005, 3, 3357, 2.7 g, 11.4 mmol) indichloromethane (30 mL), boron trifluoride etherate (0.01 mL, 0.11 mmol)was added at 0° C. followed by absolute ethanol (1.05 g, 22.9 mmol). Thereaction mixture was stirred at room temperature for an hour, afterwhich the solution was quenched with saturated bicarbonate solution (2mL), extracted with dichloromethane (3×25 mL), organic layers werewashed with water (25 mL), brine solution (25 mL) and dried over sodiumsulfate. The removal of solvents afforded crude product, which waspurified by silica gel column chromatography using a gradient of ethylacetate in pet. ether. Yield: 2.0 g (63%). ¹H NMR (400 MHz, DMSO-d₆) δ:1.08 (t, 3H), 3.38-3.46 (m, 2H), 3.57-3.63 (m, 2H), 3.70 (s, 3H),4.26-4.31 (m, 1H), 5.04 (s, 2H), 7.30-7.39 (m, 5H), 7.73 (d, 1H).

Intermediate 111 Benzyl [(2R)-1-ethoxy-3-hydroxypropan-2-yl]carbamate

To a stirred solution of Intermediate 110 (2.0 g, 7.10 mmol) in a 9:1mixture of tetrahydrofuran and methanol (20 mL), sodium borohydride(0.54 g, 14.21 mmol) was added in portion at 0° C. and the mixture wasstirred at the room temperature for 2 hours. The reaction was quenchedwith water (5 mL), poured into ice-cooled water (25 mL) and extractedwith ethyl acetate (3×20 mL). The organic layers were washed with water(20 mL), brine solution (20 mL) and dried over sodium sulfate. Removalof solvent afforded crude product which was purified over silica gelcolumn chromatography using a gradient of ethyl acetate in pet. ether.Yield: 0.7 g (35%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.07 (t, 3H), 3.35-3.46(m, 6H), 3.55-3.60 (m, 1H), 4.65 (t, 1H), 5.00 (s, 2H), 7.02 (d, 1H),7.27-7.35 (m, 5H).

Intermediate 112 (4S)-4-(Ethoxymethyl)-1,3-oxazolidin-2-one

To a stirred solution of Intermediate 111 (1.20 g, 4.49 mmol) intetrahydrofuran (50 mL), 1M solution of potassium t-butoxide intetrahydrofuran (9.0 mL, 8.98 mmol) was added at 0° C. and the mixturewas stirred at room temperature for 30 minutes. The reaction mixture wasquenched with water (25 mL) at 0° C. and extracted with ethyl acetate(3×25 mL). The combined organic layers were washed with water (20 mL),brine solution (20 mL) and dried over sodium sulfate and the solventswere removed under vacuum. The crude product obtained was purified bysilica gel flash column chromatography using a gradient of ethyl acetatein pet. ether. Yield: 0.31 g (48%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.09(t, 3H), 3.45 (q, 2H), 3.86 (quin, 1H), 3.99 (dd, 1H), 4.31 (t, 1H),7.72 (br s, 1H). Note: two of the ring CH₂ protons merged with theDMSO-d₆ water peak.

Intermediate 113(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-(ethoxymethyl)-1,3-oxazolidin-2-one

To a stirred solution of sodium hydride (0.06 g, 2.19 mmol) in dimethylformamide (15 mL), a solution of Intermediate 112 (0.32 g, 2.19 mmol) indimethyl formamide (15 mL) was added slowly at 0° C. over a period of 10minutes and the mixture was stirred at the room temperature for 1 hour.A solution of Intermediate 11 (0.60 g, 1.68 mmol) in dimethyl formamide(15 mL) was added at the same temperature and the mixture was heated at90° C. for 3 hours. The reaction was quenched with saturated ammoniumchloride solution (10 mL) and extracted with ethyl acetate (3×10 mL).The combined organic layers were dried over anhydrous sodium sulfate andthe solvents were removed under vacuum. The crude product was purifiedby silica gel column chromatography using a gradient of ethyl acetate inpet. ether and the product obtained as colorless solid. Yield: 0.20 g(25%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.00 (t, 3H), 1.12 (br s, 6H),2.89-2.91 (m, 2H), 3.19-3.26 (m, 2H), 3.37-3.46 (m, 2H), 3.58-3.61 (m,1H), 3.83-3.88 (m, 1H), 3.93-4.09 (m, 6H), 4.43 (dd, 1H), 4.67-4.70 (m,2H), 6.16 (s, 1H), 8.27 (s, 1H). MS (ES) MH⁺: 466.5 for C₂₂H₂₈FN₃O₇.

Intermediate 114 MethylN-[(benzyloxy)carbonyl]-O-(2-methoxyethyl)-L-serinate

Intermediate 114 was synthesized following the procedure described forthe preparation of Intermediate 110 using (S)-1-benzyl 2-methylaziridine-1,2-dicarboxylate (2.0 g, 8.03 mmol) and 2-methoxy ethanol(4.2 mL, 53.15 mmol). Yield: 2.0 g (80%). ¹H NMR (300 MHz, DMSO-d₆) δ:3.16 (s, 3H), 3.38-3.41 (m, 2H), 3.42-3.52 (m, 2H), 3.55-3.65 (m, 4H),4.26-4.29 (m, 1H), 4.47-4.48 (m, 1H), 5.03 (s, 2H), 7.21-7.34 (m, 5H),7.71 (d, 1H).

Intermediate 115 Benzyl[(2R)-1-hydroxy-3-(2-methoxyethoxy)propan-2-yl]carbamate

Intermediate 115 was synthesized following the procedure described forthe preparation of Intermediate 111 using Intermediate 114 (2.0 g, 6.43mmol). Yield: 1.0 g (54%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.23 (s, 3H),3.40-3.41 (m, 2H), 3.44-3.47 (m, 2H), 3.51-3.54 (m, 2H), 3.58-3.62 9 m,1H), 4.47 (d, 1H), 4.66 (t, 1H), 4.99 (s, 2H), 7.03 (d, 1H), 7.19-7.34(m, 5H).

Intermediate 116 Benzyl[(2R)-1-hydroxy-3-(2-methoxyethoxy)propan-2-yl]carbamate

Intermediate 116 was synthesized following the procedure described forthe preparation of Intermediate 112 using Intermediate 115 (1.0 g, 3.50mmol) except the crude product was taken to the next step withoutpurification. Yield: 0.32 g (crude).

Intermediate 117(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-4-[(2-methoxyethoxy)methyl]-1,3-oxazolidin-2-one

Intermediate 117 was synthesized following the procedure described forthe preparation of Intermediate 113 using Intermediate 116 (0.32 g, 1.82mmol) and Intermediate 11 (0.50 g, 1.40 mmol). A mixture of the productwas eluted from silica gel column with methanol. The UPLC analysisshowed that the fraction contained 37% product which was taken to thenext step without further purification. Yield: 0.15 g (37% product). MS(ES) MH⁺: 496.5 for C₂₃H₃₀FN₃O₈.

Intermediate 1185-(1,3-Dioxolan-2-yl)-2,3,4-Trifluoro-N′-hydroxy-N-[(2S)-1-hydroxybut-3-en-2-yl]benzenecarboximidamide

Intermediate 118 was prepared from Intermediate 16 (2.0 g, 7.1 mmol) and(2S)-2-aminobut-3-en-1-ol (0.74 g, 8.54 mmol, prepared according to theliterature procedure, Eur. J. Chem. 2006, 12, 6607-6620) using a methodsimilar to the one described for the synthesis of Intermediate 71.Yield: 1.4 g (59%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.36-3.40 (m, 3H),3.95-4.05 (m, 4H), 4.83-5.00 (m, 3H), 5.87-5.90 (m, 1H), 6.01 (s, 1H),7.26 (t, 1H), 8.30 (s, 1H), 10.12 (s, 1H). MS (ES) MH⁺: 333.3 forC₁₄H₁₅F₃N₂O₄.

Intermediate 119(2S)-2-{[5-(1,3-Dioxolan-2-yl)-6,7-difluoro-1,2-benzoxazol-3-yl]amino}but-3-en-1-ol

Intermediate 119 was prepared from Intermediate 118 (1.4 g, 4.2 mmol)using a method similar to the one described for the synthesis ofIntermediate 72. Yield: 0.75 g (57%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.56(t, 2H), 4.01-4.14 (m, 5H), 4.92 (t, 1H), 5.17 (d, 1H), 5.29 (d, 1H),5.90 (ddd, 1H), 6.09 (s, 1H), 7.34 (d, 1H), 8.07 (d, 1H). MS (ES) MH⁺:313.3 for C₁₄H₁₄F₂N₂O₄.

Intermediate 120(4S)-3-[5-(1,3-Dioxolan-2-yl)-6,7-difluoro-1,2-benzoxazol-3-yl]-4-ethenyl-1,3-oxazolidin-2-one

Intermediate 120 was prepared from Intermediate 119 (0.75, 2.4 mmol)using a method similar to the one described for the synthesis ofIntermediate 73. Yield: 0.60 g (74%). ¹H NMR (400 MHz, DMSO-d₆) δ:4.00-4.08 (m, 4H), 4.33 (dd, 1H), 4.79 (t, 1H), 5.17 (q, 1H), 5.32 (d,1H), 5.40 (d, 1H), 5.93 (ddd, 1H), 6.10 (s, 1H), 8.23-8.25 (m, 1H).Yield: 0.60 g (74%). MS (ES) MH⁺: 339.2 for C₁₅H₁₂F₂N₂O₅.

Intermediate 121(R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(difluoromethyl)oxazolidin-2-one

To a stirred solution of Intermediate 120 (0.50 g, 0.30 mmol) in a 2:1mixture of tetrahydrofuran and water (20 mL), osmium (IV) oxide (0.2 mL,2.5% solution in t-butanol) was added. The resulting mixture was stirredat room temperature for 10 minutes. To this, sodium metaperiodate (3.16g, 14.75 mmol) was added portion wise over a period of an hour and thereaction mixture was stirred for an additional 16 hours. The reactionmixture was poured into an ice water (15 mL) and extracted withdichloromethane (3×15 ml), washed with water (15 mL), brine and theorganic layer was dried over sodium sulfate. Solvents were removed undervacuum at 10° C. and the resulting residue was dissolved indichloromethane (15 mL). Diethylaminosulfur trifluoride (1 mL) was addedat −10° C. and the resulting mixture was stirred at the room temperaturefor 6 hours before quenching with ice-cooled water (10 mL). The organiclayer was washed with saturated sodium bicarbonate solution (5 mL),water (5 mL), brine (5 mL) and the organic layer was dried over sodiumsulfate. Removal of solvent under vacuum afforded the title compoundwhich was taken to the next step without further purification. Yield:0.25 g (47%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.99-4.08 (m, 4H), 4.69-4.79(m, 2H), 5.08-5.15 (m, 1H), 6.10 (s, 1H), 6.59 (dt, 1H), 8.28 (dd, 1H).¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −130.0 (d), 132.4 (d), −139.9 (d),−160.7 (d). MS (ES) MH⁺: 363.3 for C₁₄H₁₀F₄N₂O₅.

Intermediate 122(R)-3-(4-(Difluoromethyl)-2-oxooxazolidin-3-yl)-6,7-difluorobenzo[d]isoxazole-5-carbaldehyde

An amount of 6 N hydrochloric acid (2.0 mL) was added to a stirredsolution of Intermediate 121 (0.25 g, 0.69 mmol) in 1,4-dioxane (10 mL)at 0° C., and the mixture was stirred at room temperature for 8 hours.The mixture was poured into ice-cooled water (25 mL) and extracted withethyl acetate (2×50 ml). The combined organic layers were washed withwater (15 mL) and brine solution (15 mL before drying over Na₂SO₄.Removal of solvent afforded the title product. Yield: 0.20 g (91%). ¹HNMR (300 MHz, DMSO-d₆) δ: 4.03-4.04 (m, 1H), 4.71-4.81 (m, 1H),5.11-5.17 (m, 1H), 6.60 (t, 1H), 8.68 (d, 1H), 10.19 (s, 1H). MS (ES)MH⁺: 319.2 for C₁₂H₆F₄N₂O₄.

Intermediate 123(3-((R)-4-(Difluoromethyl)-2-oxooxazolidin-3-yl)-6-((2R,6R)-2,6-dimethylmorpholino)-7-fluorobenzo[d]isoxazole-5-carbaldehyde

A stirred solution of Intermediate 122 (0.2 g, 0.63 mmol), diisopropylethylamine (0.15 g, 1.2 mmol) and (2R,6R)-2,6-dimethylmorpholine (80 mg,0.67 mmol) in acetonitrile (5 mL) was heated at 80° C. for 16 hours in asealed tube. After cooling to room temperature, the volatiles wereremoved under vacuum. The crude product was purified by chromatographyover silica gel using a gradient of CHCl₃ in ethyl acetate to give thetitle compound as pale yellow solid. Yield: 0.16 g (62%). ¹H NMR (300MHz, DMSO-d₆) δ: 1.20 (d, 6H), 3.02-3.05 (m, 2H), 3.38-3.41 (m, 2H),4.10-4.16 (m, 2H), 4.70-4.77 (m, 2H), 5.11-5.15 (m, 1H), 6.47 (dt, 1H),8.54 (s, 1H), 10.31 (s, 1H). MS (ES) MH⁺: 414.4 for C₁₈H₁₈F₃N₃O₅.

Intermediate 124(S)—N-(1-Cyclopropyl-2-hydroxyethyl)-5-(1,3-dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxybenzimidamide

Intermediate 124 was synthesized following the procedure described forthe preparation of Intermediate 118 using(S)-2-amino-2-cyclopropylethanol (1.38 g, 13.30 mmol) and Intermediate16 (2.50 g, 8.89 mmol). Yield: 2.2 g (72%). ¹H NMR (300 MHz, DMSO-d₆) δ:−0.79-0.89 (m, 1H), −0.92-0.10 (m, 1H), 0.31 (d, 2H), 0.88-0.90 (m, 1H),2.15-2.30 (m, 1H), 3.39 (t, 2H), 3.94-4.06 (m, 4H), 4.71 (t, 1H), 5.81(d, 1H), 6.02 (s, 1H), 7.30 (t, 1H), 9.98 (s, 1H).

Intermediate 125(S)-2-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-2-cyclopropylethanol

Intermediate 125 was synthesized following the procedure described forthe preparation of Intermediate 119 using Intermediate 124 (2.20 g, 6.40mmol). Yield: 1.80 g (87%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.23-0.25 (m,1H), 0.37-0.45 (m, 3H), 1.01-1.12 (m, 1H), 3.03-3.05 (m, 1H), 3.53-3.56(m, 1H), 3.64-3.65 (m, 1H), 4.03-4.10 (m, 4H), 4.75 (t, 1H), 6.08 (s,1H), 7.16 (d, 1H), 8.05 (dd, 1H). MS (ES) MH⁺: 327.3 for C₁₅H₁₆F₂N₂O₄.

Intermediate 126(S)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-cyclopropyloxazolidin-2-one

Intermediate 126 was synthesized following the procedure described forthe preparation of Intermediate 120 using Intermediate 125 (1.20 g, 3.67mmol). Yield: 1.10 g (85%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.28-0.31 (m,1H), 0.42-0.44 (m, 1H), 0.53-0.56 (m, 2H), 1.21-1.23 (m, 1H), 4.01-4.08(m, 4H), 4.21-4.25 (m, 1H), 4.30-4.33 (m, 1H), 4.70 (t, 1H), 6.10 (s,1H), 8.21 (dd, 1H). MS (ES) MH⁺: 353.3 for C₁₆H₁₄F₂N₂O₅.

Intermediate 127(S)-3-(4-Cyclopropyl-2-oxooxazolidin-3-yl)-6,7-difluorobenzo[d]isoxazole-5-carbaldehyde

Intermediate 127 was synthesized following the procedure described forthe preparation of Intermediate 122 using Intermediate 126 (1.10 g, 3.12mmol). Yield: 0.91 g (95%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.30-0.34 (m,1H), 0.44-0.49 (m, 1H), 0.56-0.62 (m, 2H), 1.21-1.25 (m, 1H), 4.24-4.28(m, 1H), 4.32-4.36 (m, 1H), 4.72 (t, 1H), 8.64 (dd, 1H), 10.20 (s, 1H).MS (ES) MH⁺: 309.3 for C₁₄H₁₀F₂N₂O₄.

Intermediate 1283-((S)-4-Cyclopropyl-2-oxooxazolidin-3-yl)-6-((2R,6R)-2,6-dimethylmorpholino)-7-fluorobenzo[d]isoxazole-5-carbaldehyde

Intermediate 128 was synthesized following the procedure described forthe preparation of Intermediate 123 using Intermediate 127. Yield: 1.0 g(86%). ¹H NMR (300 MHz, DMSO-d₆) δ: 0.30-0.34 (m, 1H), 0.44-0.49 (m,1H), 0.57-0.60 (m, 2H), 1.20 (d, 6H), 2.99-3.03 (m, 2H), 3.31-3.39 (m,2H), 4.10-4.15 (m, 2H), 4.19-4.33 (m, 2H), 4.69 (t, 1H), 8.30 (s, 1H),8.47 (s, 1H), 10.31 (s, 1H). MS (ES) MH⁺: 404.4 for C₂₀H₂₂FN₃O₅.

Intermediate 1295-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-(2-hydroxy-2-(pyridin-2-yl)ethyl)benzimidamide

Intermediate 129 was synthesized following the procedure described forthe preparation of Intermediate 118 using2-amino-1-(pyridin-2-yl)ethanol (1.35 g, 6.40 mmol) and Intermediate 16(1.50 g, 5.33 mmol). Yield: 1.70 g (83%). ¹H NMR (300 MHz, DMSO-d₆) δ:3.02-3.09 (m, 1H), 3.19-3.39 (m, 1H), 3.96-4.05 (m, 4H), 4.55 (d, 1H),5.72 (d, 1H), 6.02 (m, 2H), 7.10 (t, 1H), 7.22 (t, 1H), 7.41 (t, 1H),7.74 (t, 1H), 8.37 (d, 1H), 9.96 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆)δ: −134.3 (dd), −138.3 (dd), −159.91 (d). MS (ES) MH⁺: 384.3 forC₁₇H₁₆F₃N₃O₄.

Intermediate 1302-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-1-(pyridin-2-yl)ethanol

Intermediate 130 was synthesized following the procedure described forthe preparation of Intermediate 119 using Intermediate 129 (1.60 g, 4.17mmol). Yield: 1.30 g (86%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.66 (dd, 1H),4.00-4.09 (m, 4H), 4.92 (t, 1H), 5.75 (d, 1H), 6.08 (s, 1H), 7.28 (dd,1H), 7.50 (t, 1H), 7.55 (d, 1H), 7.80 (t, 1H), 8.04 (d, 1H), 8.52 (d,1H). Note: one more CH proton merged with the DMSO-d₆ peak. MS (ES) MH⁺:364.3 for C₁₇H₁₅F₂N₃O₄.

Intermediate 1313-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-5-(pyridin-2-yl)oxazolidin-2-one

Intermediate 131 was synthesized following the procedure described forthe preparation of Intermediate 120 using Intermediate 130 (1.20 g, 3.30mmol). Yield: 1.20 g (93%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.98-4.09 (m,4H), 4.22-4.35 (m, 1H), 4.58 (t, 1H), 6.01 (dd, 1H), 6.10 (s, 1H), 7.46(dd, 1H), 7.65 (d, 1H), 7.91 (t, 1H), 8.47 (d, 1H), 8.65 (d, 1H). ¹⁹FNMR (376.5 MHz, DMSO-d₆) δ: −140.4 (d), −161.10 (d). MS (ES) MH⁺: 390.3for C₁₈H₁₃F₂N₃O₅

Intermediate 1326,7-Difluoro-3-(2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 132 was synthesized following the procedure described forthe preparation of Intermediate 122 using Intermediate 131 (1.20 g, 3.09mmol). Yield: 1.0 g (94%). ¹H NMR (400 MHz, DMSO-d₆) δ: 4.35 (dd, 1H),4.60 (t, 1H), 6.04 (dd, 1H), 7.45-7.49 (m, 1H), 7.70 (d, 1H), 7.93 (t,1H), 8.65 (d, 1H), 8.86 (d, 1H), 10.20 (s, 1H). ¹⁹F NMR (376.5 MHz,DMSO-d₆) δ: −143.1 (d), −160.4 (d). MS (ES) MH⁺: 346.3 for C₁₆H₉F₂N₃O₄.

Intermediate 1336-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-(2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 133 was synthesized following the procedure described forthe preparation of Intermediate 123 using Intermediate 132 (1.0 g, 2.89mmol). Yield: 1.0 g (78%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.21 (d, 6H),3.00-3.04 (m, 2H), 3.37-3.40 (m, 2H), 4.12-4.15 (m, 2H), 4.33 (dd, 1H),4.57 (t, 1H), 6.02 (dd, 1H), 7.46-7.48 (m, 1H), 7.66 (d, 1H), 7.91 (t,1H), 8.65 (d, 1H), 8.71 (s, 1H), 10.30 (s, 1H). MS (ES) MH⁺: 441.4 forC₂₂H₂₁FN₄O₅.

Intermediate 1345-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-(2-hydroxy-1-(pyridin-2-yl)ethyl)benzimidamide

Intermediate 134 was synthesized following the procedure described forthe preparation of Intermediate 118 using Intermediate 16 (1.0 g, 3.55mmol). Yield: 1.05 g (78%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.59 (t, 2H),3.93-4.08 (s, 5H), 4.94 (t, 1H), 5.96 (s, 1H), 6.41 (d, 1H), 7.09 (t,1H), 7.20-7.25 (m, 2H), 7.72 (t, 1H), 8.43 (d, 1H), 10.20 (s, 1H). MS(ES) MH⁺: 384.3 for C₁₇H₁₆F₃N₃O₄.

Intermediate 1352-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-2-(pyridin-2-yl)ethanol

Intermediate 135 was synthesized following the procedure described forthe preparation of Intermediate 119 using Intermediate 134 (1.60 g, 2.60mmol). Yield: 0.78 g (73%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.79-3.85 (m,2H), 4.03-4.14 (m, 4H), 4.74 (q, 1H), 5.02 (t, 1H), 6.10 (s, 1H), 7.26(dd, 1H), 7.41 (d, 1H), 7.72 (t, 1H), 7.74 (dd, 1H), 8.17 (d, 1H), 8.54(d, 1H). MS (ES) MH⁺: 364.3 for C₁₇H₁₅F₂N₃O₄.

Intermediate 1363-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(pyridin-2-yl)oxazolidin-2-one

Intermediate 136 was synthesized following the procedure described forthe preparation of Intermediate 120 using Intermediate 135 (1.0 g, 2.75mmol). Yield: 0.90 g (84%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.99-4.10 (m,4H), 4.44 (dd, 1H), 4.97 (t, 1H), 5.75 (dd, 1H), 6.09 (s, 1H), 7.34 (dd,1H), 7.55 (d, 1H), 7.82 (t, 1H), 8.41 (d, 1H), 8.51 (d, 1H). MS (ES)MH⁺: 390.3 for C₁₈H₁₃F₂N₃O₅.

Intermediate 1376,7-Difluoro-3-(2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 137 was synthesized following the procedure described forthe preparation of Intermediate 122 using Intermediate 136 (0.90 g, 2.31mmol). Yield: 0.75 g (94%). ¹H NMR (400 MHz, DMSO-d₆) δ: 4.49 (dd, 1H),5.01 (t, 1H), 5.79 (dd, 1H), 7.35-7.38 (m, 1H), 7.59 (d, 1H), 7.85 (dt,1H), 8.54 (d, 1H), 8.83 (d, 1H), 10.20 (s, 1H). MS (ES) MH⁺: 346.3 forC₁₆H₉F₂N₃O₄.

Intermediate 1386-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-(2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 138 was synthesized following the procedure described forthe preparation of Intermediate 123 using Intermediate 137 (0.75 g, 2.17mmol). Yield: 0.85 g (89%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.20 (d, 6H),2.96-3.00 (m, 2H), 3.31-3.36 (m, 2H), 4.00-4.13 (m, 2H), 4.45 (dd, 1H),4.98 (t, 1H), 5.75 (dd, 1H), 7.33 (t, 1H), 7.54 (d, 1H), 7.82 (t, 1H),8.51 (d, 1H), 8.65 (d, 1H), 10.30 (s, 1H). MS (ES) MH⁺: 441.4 forC₂₂H₂₁FN₄O₅.

Intermediate 1395-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-(2-hydroxy-1-(pyridin-4-yl)ethyl)benzimidamide

Intermediate 139 was synthesized following the procedure described forthe preparation of Intermediate 118 using Intermediate 16 (1.08 g, 3.84mmol). Yield: 0.91 g (62%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.55-3.68 (m,2H), 3.82-3.92 (m, 4H), 3.98-4.08 (m, 1H), 5.05 (t, 1H), 5.93 (s, 1H),6.51 (d, 1H), 6.92-6.96 (m, 1H), 7.11 (d, 2H), 8.41 (d, 2H), 10.30 (s,1H). MS (ES) MH⁺: 384.3 for C₁₇H₁₆F₃N₃O₄.

Intermediate 1402-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-2-(pyridin-4-yl)ethanol

Intermediate 140 was synthesized following the procedure described forthe preparation of Intermediate 119 using Intermediate 139 (0.90 g, 2.34mmol). Yield: 0.60 g (71%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.73 (t, 2H),4.00-4.12 (m, 4H), 4.66 (q, 1H), 5.12 (t, 1H), 6.08 (s, 1H), 7.39 (d,2H), 7.89 (d, 1H), 8.11 (t, 1H), 8.49 (d, 2H). MS (ES) MH⁺: 364.3 forC₁₇H₁₅F₂N₃O₄.

Intermediate 1413-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(pyridin-4-yl)oxazolidin-2-one

Intermediate 141 was synthesized following the procedure described forthe preparation of Intermediate 120 using Intermediate 140 (0.60 g, 1.65mmol). Yield: 0.61 g (95%). ¹H NMR (400 MHz, DMSO-d₆) δ: 4.01-4.10 (m,4H), 4.36 (dd, 1H), 5.02 (t, 1H), 5.75 (dd, 1H), 6.10 (s, 1H), 7.49 (dd,2H), 8.38 (dd, 1H), 8.55 (dd, 2H). MS (ES) MH⁺: 390.3 for C₁₈H₁₃F₂N₃O₅.

Intermediate 1426,7-Difluoro-3-(2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 142 was synthesized following the procedure described forthe preparation of Intermediate 122 TQ-100-14-V using Intermediate 141(0.60 g, 1.54 mmol). Yield: 0.47 g (88%). ¹H NMR (400 MHz, DMSO-d₆) δ:4.40 (dd, 1H), 5.05 (t, 1H), 5.77 (dd, 1H), 7.51 (d, 2H), 8.57 (d, 2H),8.78 (d, 1H), 10.22 (s, 1H). MS (ES) MH⁺: 346.3 for C₁₆H₉F₂N₃O₄.

Intermediate 1436-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-(2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 143 was synthesized following the procedure described forthe preparation of Intermediate 123 using Intermediate 142 (0.46 g, 1.33mmol). Yield: 0.52 g (89%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.36 (d, 6H),2.87-2.99 (m, 2H), 3.31-3.37 (m, 2H), 4.08-4.12 (m, 2H), 4.36 (t, 1H),5.01 (t, 1H), 5.74 (t, 1H), 7.46 (d, 2H), 8.54 (d, 2H), 8.62 (d, 1H),10.31 (s, 1H). MS (ES) MH⁺: 441.4 for C₂₂H₂₁FN₄O₅.

Intermediate 144 (2R,3R)-2-Amino-3-methoxybutan-1-ol

To a stirred solution of (2S,3R)-methyl 2-amino-3-methoxybutanoate (10.0g, 75.19 mmol) in tetrahydrofuran (150 mL), sodium borohydride (10.28 g,270.7 mmol) and iodine (24.7 g, 97.77 mmol) was added and the mixturewas refluxed over a period of 16 hours. The mixture was filtered and thevolatiles were removed under vacuum and the crude product was taken tothe next step without further purification. Yield: 7.0 g (78%).

Intermediate 1455-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-((2R,3R)-1-hydroxy-3-methoxybutan-2-yl)benzimidamide

To a stirred solution of Intermediate 144 (7.0 g, 58.82 mmol) indimethyl formamide (25 mL), triethylamine (11.91 g, 117.64 mmol) wasadded and the mixture was stirred at the room temperature for 20minutes. To this solution, Intermediate 16 (3.50 g, 12.43 mmol) wasadded and the mixture was stirred at the room temperature for another 2hours. The mixture was poured into ice cold water (50 mL) and extractedwith ethyl acetate (3×50 mL). The organic layers were washed with water(2×25 mL), brine solution (25 mL) and dried over sodium sulfate. Removalof solvent afforded crude product which was purified by silica gel flashcolumn chromatography using a gradient of ethyl acetate in pet. ether.Yield: 1.8 g (40%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.02 (d, 3H), 2.72-2.74(m, 1H), 3.22 (s, 3H), 3.41-3.43 (m, 1H), 3.98-4.05 (m, 4H), 4.69 (t,1H), 5.51 (d, 1H), 6.04 (s, 1H), 7.34 (t, 1H), 10.08 (s, 1H). Note: NHand OH protons did not appear. ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −134.33(m), −138.45 (m), −159.75 (m). MS (ES) MH⁺: 365.2 for C₁₅H₁₉F₃N₂O₅.

Intermediate 146(2R,3R)-2-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-3-methoxybutan-1-ol

To a stirred solution of Intermediate 145 (1.8 g g, 4.96 mmol) indimethyl formamide (20 mL), cesium carbonate (3.55 g, 10.90 mmol) wasadded and the mixture was stirred at the room temperature for 16 hours.Water (10 mL) was added to the mixture and extracted with ethyl acetate(3×25 mL). The organic layers were washed with water (2×15 mL), brinesolution (15 mL) and dried over sodium sulfate. Removal of the solventafforded crude product which was further purified by silica gel flashcolumn chromatography using 75% ethyl acetate in pet.ether. Yield: 1.30g (76%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.12 (d, 3H), 3.30 (s, 3H),3.51-3.52 (m, 1H), 3.59-3.66 (m, 3H), 4.01-4.10 (m, 4H), 4.74 (t, 1H),6.07 (s, 1H), 7.12 (d, 1H), 8.16 (d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆)δ: −143.58 (d), −162.18 (d). MS (ES) MH⁺: 345.2 for C₁₅H₁₈F₂N₂O₅.

Intermediate 147(R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-((R)-1-methoxyethyl)oxazolidin-2-one

To a stirred solution of Intermediate 146 (1.30 g, 3.78 mmol) inacetonitrile (20 mL), triethylamine (0.76 g, 7.56 mmol) was added at 0°C. and the mixture was stirred for 15 minutes. To this solution,bis(2,5-dioxopyrrolidin-1-yl) carbonate (or) disuccinimidyl carbonate(1.06 g, 4.16 mmol) was added at 0° C. and the mixture was stirred atthe room temperature for 16 hours. The volatiles were removed undervacuum and the residue was dissolved in ethyl acetate (25 mL), washedwith water (10 mL), brine solution (10 mL) and dried over sodiumsulfate. Removal of solvent under vacuum afforded pale yellow solidwhich was purified in a Combi-Flash instrument using a gradient of ethylacetate in pet. ether. Yield: 0.40 g (29%). ¹H NMR (300 MHz, DMSO-d₆) δ:1.03 (d, 3H), 3.32 (s, 3H), 3.96-4.08 (m, 4H), 4.49-4.53 (m, 1H), 4.63(t, 1H), 4.78-4.83 (m, 1H), 6.08 (s, 1H), 8.27 (d, 1H). ¹⁹F NMR (376.5MHz, DMSO-d₆) δ: −140.41 (d), −161.03 (d). MS (ES) MH⁺: 371.3 forC₁₆H₁₆F₂N₂O₆.

Intermediate 1486,7-Difluoro-3-((R)-4-((R)-1-methoxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

To a stirred solution of Intermediate 147 (0.40 g, 1.08 mmol) in1,4-dioxane (4 mL), 6N hydrochloric acid (2 mL) was added at 0° C. andthe mixture was stirred at the room temperature for 1 hour. The mixturewas poured into ice-cooled water (25 mL) and extracted with ethylacetate (3×25 mL). The organic layers were washed with water (15 mL),brine solution (15 mL) and dried over sodium sulfate. Removal of thesolvent afforded the title product. Yield: 0.35 g (99%). ¹H NMR (300MHz, DMSO-d₆) δ: 1.03 (d, 3H), 3.32 (s, 3H), 3.96-4.08 (m, 4H),4.49-4.53 (m, 1H), 4.63 (t, 1H), 4.78-4.83 (m, 1H), 6.08 (s, 1H), 8.27(d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −140.41 (d), −161.03 (d). MS(ES) MH⁺: 327.2 for C₁₄H₁₂F₂N₂O₅.

Intermediate 1496-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((R)-4-((R)-1-methoxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

To a stirred solution of Intermediate 148 (0.35 g, 1.07 mmol) inacetonitrile (4 mL), was added diisopropyl ethylamine (0.21 g, 1.61mmol) followed by (2R,6R)-2,6-dimethylmorpholine (0.13 g, 1.07 mmol) andthe mixture was heated at 80° C. for 16 hours in a sealed tube. It wascooled to room temperature and the volatiles were removed under vacuumto obtain the crude product was purified in a Combi-Flash instrumentusing a gradient of ethyl acetate in pet. ether to obtain the titlecompound as pale yellow solid. Yield: 0.25 g (56%). ¹H NMR (300 MHz,DMSO-d₆) δ: 1.02 (d, 3H), 1.20 (d, 6H), 2.97-3.03 (m, 2H), 3.28 (s, 3H),3.35-3.39 (m, 2H), 3.97-4.01 (m, 1H), 4.10-4.15 (m, 2H), 4.51-4.54 (m,1H), 4.63 (t, 1H), 4.81-4.84 (m, 1H), 8.54 (s, 1H), 10.29 (s, 1H). ¹⁹FNMR (376.5 MHz, DMSO-d₆) δ: −146.80 (s). MS (ES) MH⁺: 422.5 forC₂₀H₂₄FN₃O₆.

Intermediate 150 Benzyl ((2R,3S)-1-hydroxy-3-methoxybutan-2-yl)carbamate

To a stirred solution of (2S,3S)-methyl2-(((benzyloxy)carbonyl)amino)-3-methoxybutanoate (prepared according tothe literature procedure: Bioorg. Med. Chem. Lett. 15 (2005) 1447-1449,1.60 g, 5.68 mmol) in a 3:1 mixture of tetrahydrofuran and methanol (12mL), sodium borohydride (0.43 g, 11.38 mmol) was added and the mixturewas stirred at room temperature for 2 hours. The volatiles were removedand the residue was dissolved in ethyl acetate (25 mL) and washed withbrine (10 mL). Removal of the solvent afforded crude product which waspurified by silica gel column chromatography using a gradient of ethylacetate in pet. ether. Yield: 1.32 g (92%). ¹H NMR (400 MHz, DMSO-d₆) δ:1.01 (d, 3H), 3.22 (s, 3H), 3.36-3.42 (m, 3H), 3.57-3.60 (m, 1H), 4.57(t, 1H), 5.02 (s, 2H), 6.98-7.01 (m, 1H), 7.31-7.37 (m, 5H). MS (ES)MH⁺: 254.4 for C₁₃H₁₉F₃NO₄.

Intermediate 151 (2R,3S)-2-Amino-3-methoxybutan-1-ol

To a stirred solution of Intermediate 150 (1.32 g, 5.20 mmol) in ethylacetate (50 mL), and 10% palladium on charcoal (0.13 g, 10 wt %) wasadded and the mixture was stirred at the room temperature under 20 mmpressure of hydrogen for 6 hours. The mixture was filtered and thevolatiles were removed under vacuum and the crude product was taken tothe next step without further purification. Yield: 0.47 g (47%)

Intermediate 1525-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-((2R,3S)-1-hydroxy-3-methoxybutan-2-yl)benzimidamide

Intermediate 152 was synthesized following the procedure described forthe preparation of Intermediate 145 using Intermediate 151 (0.47 g, 4.02mmol). Yield: 0.50 g (35%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.00 (d, 3H),3.02 (s, 3H), 3.27-3.32 (m, 2H), 3.41 (d, 2H), 3.96-4.06 (m, 4H), 4.68(t, 1H), 5.67 (d, 1H), 6.03 (s, 1H), 7.33-7.34 (m, 1H), 10.03 (s, 1H).¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −134.26 (m), −138.79 (m), −160.03 (m).MS (ES) MH⁺: 365.5 for C₁₅H₁₉F₃N₂O₅.

Intermediate 153(2R,3S)-2-((5-(1,3-dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-3-methoxybutan-1-ol

Intermediate 153 was synthesized following the procedure described forthe preparation of Intermediate 146 using Intermediate 152 (0.50 g, 1.37mmol). Yield: 0.32 g (67%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.15 (d, 3H),3.25 (s, 3H), 3.52-3.60 (m, 4H), 3.98-4.10 (m, 4H), 4.70 (t, 1H), 6.06(s, 1H), 7.09 (d, 1H), 8.09 (d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ:−143.51 (d), −162.06 (d). MS (ES) MH⁺: 345.5 for C₁₅H₁₈F₂N₂O₅.

Intermediate 154(R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-((S)-1-methoxyethyl)oxazolidin-2-one

Intermediate 154 was synthesized following the procedure described forthe preparation of Intermediate 147 using Intermediate 153 (0.25 g, 0.72mmol). Yield: 0.08 g (30%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.11 (d, 3H),3.15 (s, 3H), 3.98-4.08 (m, 5H), 4.55-4.61 (m, 3H), 6.09 (s, 1H), 8.30(d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −140.43 (d), −161.01 (d). MS(ES) MH⁺: 371.4 for C₁₆H₁₆F₂N₂O₆

Intermediate 1556,7-Difluoro-3-((R)-4-((S)-1-methoxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 155 was synthesized following the procedure described forthe preparation of Intermediate 148 using Intermediate 154 (0.08 g, 0.22mmol). The crude product was taken to the next step withoutpurification. Yield: 0.06 g (85%).

Intermediate 1566-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((R)-4-((S)-1-methoxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 156 was synthesized following the procedure described forthe preparation of Intermediate 149 using Intermediate 155 (0.06 g, 0.18mmol). The crude product was taken to the next step withoutpurification. Yield: 0.04 g (52%). MS (ES) MH⁺: 422.5 for C₂₀H₂₄FN₃O₆

Intermediate 157 Ethyl2-((diphenylmethylene)amino)-2-(pyrazin-2-yl)acetate

A mixture of ethyl 2-((diphenylmethylene)amino)acetate (6.0 g, 22.47mmol), 2-bromopyrazine (7.1 g, 44.90 mmol), potassium carbonate (9.30 g,67.40 mmol) and tetrabutyl ammonium iodide (8.10 g, 22.40 mmol) inN-methyl-2-pyrrolidone (25 mL) was heated in a sealed tube at 110° C.for 16 hours. The mixture was poured into water (100 mL) and extractedwith ethyl acetate (3×50 mL). The organic layers were washed with brine(25 mL) and dried over sodium sulfate. Removal of solvent under vacuumafforded crude product which was purified in Combi-Flash instrumentusing a gradient of methanol in chloroform. Yield: 4.90 g (63%). ¹H NMR(300 MHz, DMSO-d₆) δ: 1.16 (t, 3H), 4.07 (q, 2H), 5.26 (s, 1H), 7.18(dd, 2H), 7.38-7.61 (m, 8H), 8.56 (d, 1H), 8.57 (d, 1H), 8.60 (s, 1H).MS (ES) MH⁺: 346.3 for C₂₁H₁₉N₃O₂.

Intermediate 158 Ethyl 2-amino-2-(pyrazin-2-yl)acetate

To a stirred solution of Intermediate 157 (4.9 g, 14.20 mmol) in dioxane(20 mL), 3N hydrochloric acid (20 mL) was added and the mixture wasstirred at room temperature for 3 hours. The volatiles were removedcompletely under vacuum and the product obtained as its hydrochloridesalt has been taken to the next step without purification. Yield: 2.4 g(92%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.13 (t, 3H), 4.19 (q, 2H), 5.66 (s,1H), 8.73-8.77 (m, 2H), 8.95 (d, 1H), 9.19 (br s, 3H). MS (ES) MH⁺:182.3 for C₈H₁₁N₃O₂.

Intermediate 159 Ethyl2-((tert-butoxycarbonyl)amino)-2-(pyrazin-2-yl)acetate

To a stirred solution of Intermediate 158 (2.4 g, 11.60 mmol) indichloromethane (25 mL), di-t-butyl dicarbonate (2.88 g, 12.76 mmol) andtriethylamine (5 mL) were added and the mixture was refluxed for 2hours. The volatiles were removed completely under vacuum and the crudeproduct was taken to the next step without purification. Yield: 2.80 g(90%).

Intermediate 160 tert-Butyl (2-hydroxy-1-(pyrazin-2-yl)ethyl)carbamate

To a stirred solution of Intermediate 163 (2.80 g, 9.96 mmol) in a 1:1mixture of tetrahydrofuran and methanol (50 mL), sodium borohydride(0.37 g, 9.96 mmol) was added and the mixture was stirred at roomtemperature for 16 hours. The volatiles were removed under vacuum andthe residue was dissolved in ethyl acetate (25 mL) and washed with brine(10 mL). Removal of the solvent afforded crude product which was takento the next step without purification. Yield: 1.8 g (76%)

Intermediate 161 2-Amino-2-(pyrazin-2-yl)ethanol

To a stirred solution of Intermediate 160 (1.80 g, 7.50 mmol) 3Nhydrochloric acid in diethyl ether (20 mL) was added and the mixture wasstirred at the room temperature for 3 hours.

The volatiles were removed completely under vacuum and the product wastaken to the next step without purification. Yield: 1.1 g (83%). MS (ES)MH⁺: 140.2 for C₆H₉N₃O.

Intermediate 1625-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-(2-hydroxy-1-(pyrazin-2-yl)ethyl)benzimidamide

Intermediate 162 was synthesized following the procedure described forthe preparation of Intermediate 118 using Intermediate 161 (1.10 g, 6.32mmol) and Intermediate 16 (1.78 g, 6.32 mmol). Yield: 0.96 g (40%). MS(ES) MH⁺: 385.4 for C₁₆H₁₅F₃N₄O₄

Intermediate 1632-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-2-(pyrazin-2-yl)ethanol

Intermediate 163 was synthesized following the procedure described forthe preparation of Intermediate 119 using Intermediate 162 (0.96 g, 2.50mmol). Yield: 0.52 g (55%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.87 (t, 2H),4.00-4.09 (m, 4H), 4.80 (q, 1H), 5.09 (t, 1H), 6.08 (s, 1H), 7.96 (d,1H), 8.13 (d, 1H), 8.54 (d, 1H), 8.61 (d, 1H), 8.68 (s, 1H). MS (ES)MH⁺: 365.4 for C₁₆H₁₄F₂N₄O₄.

Intermediate 1643-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(pyrazin-2-yl)oxazolidin-2-one

Intermediate 164 was synthesized following the procedure described forthe preparation of Intermediate 120 using Intermediate 163 (0.25 g, 0.69mmol). Yield: 0.16 g (59%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.98-4.09 (m,4H), 4.54 (dd, 1H), 4.99 (t, 1H), 5.87 (dd, 1H), 6.09 (s, 1H), 8.39 (dd,1H), 8.61-8.63 (m, 2H), 8.86 (d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ:−140.24 (d), −160.93 (d). MS (ES) MH⁺: 391.4 for C₁₇H₁₂F₂N₄O₅.

Intermediate 1656,7-Difluoro-3-(2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 165 was synthesized following the procedure described forthe preparation of Intermediate 122 using Intermediate 164 (0.16 g, 2.41mmol). Yield: 0.12 g (86%). ¹H NMR (300 MHz, DMSO-d₆) δ: 4.56 (dd, 1H),5.01 (t, 1H), 5.88 (dd, 1H), 8.61-8.64 (m, 2H), 8.80 (d, 1H), 8.88 (d,1H), 10.18 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −142.93 (d), −160.18(d). MS (ES) MH⁺: 347.4 for C₁₅H₈F₂N₄O₄.

Intermediate 1666-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-(2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 166 was synthesized following the procedure described forthe preparation of Intermediate 123 using Intermediate 165 (0.12 g, 0.35mmol). Yield: 0.12 g (80%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.21 (d, 6H),2.98-3.00 (m, 2H), 3.31-3.33 (m, 2H, merged in DMSO peak), 4.11-4.13 (m,2H), 4.56 (dd, 1H), 5.01 (t, 1H), 5.88 (dd, 1H), 8.63-8.67 (m, 3H), 8.88(s, 1H), 10.31 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −142.93 (d),−160.18 (d). MS (ES) MH⁺: 442.5 for C₂₁H₂₀FN₅O₅.

Intermediate 1675-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-(2-hydroxy-1-(pyrimidin-2-yl)ethyl)benzimidamide

Intermediate 167 was synthesized synthesized following the proceduredescribed for the preparation of Intermediate 118 using2-amino-2-(pyrimidin-2-yl)ethanol Intermediate 161 (1.0 g, 5.7 mmol) andIntermediate 16 (1.60 g, 5.71 mmol). Yield: 1.0 g (42%). MS (ES) MH⁺:385.5 for C₁₆H₁₅F₃N₄O₄

Intermediate 1682-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-2-(pyrimidin-2-yl)ethanol

Intermediate 168 was synthesized synthesized following the proceduredescribed for the preparation of Intermediate 119 using Intermediate 167(1.0 g, 2.51 mmol). Yield: 0.42 g (45%). ¹H NMR (400 MHz, DMSO-d₆) δ:3.86-3.94 (m, 2H), 4.01-4.11 (m, 4H), 4.84-4.87 (m, 1H), 5.02 (t, 1H),6.10 (s, 1H), 7.39 (t, 1H), 7.85 (d, 1H), 8.18 (d, 1H), 8.76 (d, 2H).¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −143.35 (d), 161.90 (d). MS (ES) MH⁺:365.4 for C₁₆H₁₄F₂N₄O₄.

Intermediate 1693-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(pyrimidin-2-yl)oxazolidin-2-one

Intermediate 169 was synthesized synthesized following the proceduredescribed for the preparation of Intermediate 120 using Intermediate 168(0.34 g, 0.93 mmol). Yield: 0.25 g (70%). MS (ES) MH⁺: 391.4 forC₁₇H₁₂F₂N₄O₅.

Intermediate 1706,7-Difluoro-3-(2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 170 was synthesized following the procedure described forthe preparation of Intermediate 122 using Intermediate 169 (0.25 g, 2.41mmol). The crude product was taken to the next step withoutpurification. Yield: 0.14 g (64%). MS (ES) MH⁺: 347.4 for C₁₅H₈F₂N₄O₄.

Intermediate 1716-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-(2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 171 was synthesized following the procedure described forthe preparation of Intermediate 123 using Intermediate 170 (0.14 g, 0.26mmol). Yield: 0.12 g (63%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.22 (d, 6H),2.98-3.02 (m, 2H), 3.36-3.39 (m, 2H), 4.11-4.14 (m, 2H), 4.54 (dd, 1H),5.05 (t, 1H), 5.75 (s, 1H), 7.49-7.52 (m, 1H), 8.69 (d, 1H), 8.81-8.83(m, 2H), 10.31 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −146.69 (d). MS(ES) MH⁺: 442.5 for C₂₁H₂₀FN₅O₅.

Intermediate 172(S)-5-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-(1-hydroxybut-3-yn-2-yl)benzimidamide

Intermediate 172 was synthesized following the procedure described forthe preparation of Intermediate 118 using (S)-2-aminobut-3-yn-1-ol(prepared according to the literature procedure from Garner aldehyde;Eur. J. Org. Chem. 2009, 3619-3627, 0.30 g, 2.44 mmol) and Intermediate16 (0.65 g, 2.32 mmol). Yield: 0.53 g (65%). ¹H NMR (300 MHz, DMSO-d₆)δ: 3.16 (d, 1H), 3.50 (t, 2H), 3.60-3.70 (m, 1H), 3.98-4.05 (m, 4H),5.12 (t, 1H), 6.04-6.10 (m, 2H), 7.34 (t, 1H), 10.23 (s, 1H). ¹⁹F NMR(376.5 MHz, DMSO-d₆) δ: −133.64 (m), −138.05 (m), −159.54 (m). MS (ES)MH⁺: 331.4 for C₁₄H₁₃F₃N₂O₄.

Intermediate 173(S)-2-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)but-3-yn-1-ol

Intermediate 173 was synthesized following the procedure described forthe preparation of Intermediate 119 using Intermediate 172 (0.51 g, 1.55mmol). Yield: 0.27 g (55%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.24 (d, 1H),3.65 (t, 2H), 3.98-4.05 (m, 4H), 4.32-4.34 (m, 1H), 5.20 (t, 1H), 6.08(s, 1H), 7.70 (d, 1H), 8.01 (d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ:−142.96 (d), −161.66 (d). MS (ES) MH⁺: 311.4 for C₁₄H₁₂F₂N₂O₄.

Intermediate 174(S)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-ethynyloxazolidin-2-one

Intermediate 174 was synthesized following the procedure described forthe preparation of Intermediate 120 using Intermediate 173 (0.25 g, 0.81mmol). Yield: 0.25 g (92%). ¹H NMR (400 MHz, DMSO-d₆) δ: 3.69 (d, 1H),3.99-4.08 (m, 4H), 4.56 (dd, 1H), 4.85 (t, 1H), 5.41-5.45 (m, 1H), 6.11(s, 1H), 8.27 (dd, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −140.16 (d),−160.70 (d). MS (ES) MH⁺: 337.4 for C₁₅H₁₀F₂N₂O₅.

Intermediate 175(S)-3-(4-Ethynyl-2-oxooxazolidin-3-yl)-6,7-difluorobenzo[d]isoxazole-5-carbaldehyde

Intermediate 175 was synthesized following the procedure described forthe preparation of Intermediate 122 using Intermediate 174 (0.25 g, 0.74mmol). Yield: 0.14 g (65%). ¹H NMR (300 MHz, DMSO-d₆) δ: 3.70 (d, 1H),4.58 (dd, 1H), 4.86 (t, 1H), 5.41-5.46 (m, 1H), 8.67 (dd, 1H), 10.18 (s,1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −142.87 (d), −159.98 (d). MS (ES)MH⁺: 293.3 for C₁₃H₆F₂N₂O₄.

Intermediate 1766-((2R,6R)-2,6-dimethylmorpholino)-3-((S)-4-ethynyl-2-oxooxazolidin-3-yl)-7-fluorobenzo[d]isoxazole-5-carbaldehyde

Intermediate 176 was synthesized following the procedure described forthe preparation of Intermediate 123 using Intermediate 175 (0.14 g, 0.48mmol). Yield: 0.08 g (43%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.21 (d, 6H),2.98-3.04 (m, 2H), 3.36-3.40 (m, 2H), 3.67 (d, 1H), 4.12-4.13 (m, 2H),4.56 (dd, 1H), 4.81 (t, 1H), 5.39-5.43 (m, 1H), 8.51 (s, 1H), 10.30 (s,1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −146.52 (s). MS (ES) MH⁺: 388.5 forC₁₉H₁₈FN₃O₅.

Intermediate 177(S)-3-(7-chloro-6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)benzo[d]isoxazol-3-yl)-4-methyloxazolidin-2-one

Intermediate 177 was synthesized following the procedure described forthe preparation of Intermediate 42 using (S)-4-methyloxazolidin-2-one(synthesized according to the procedure described in Nishiyama, T.;Matsui, Shigeki; Yamada, F. J. Het. Chem. (1986), 23(5), 1427-9) andIntermediate 52. ¹H NMR (300 MHz, DMSO-d₆) δ: 1.1 (br. s., 3H) 1.3 (br.s., 3H) 1.4 (d, 3H) 2.7-2.8 (m, 1H) 2.95-3.2 (m, 2H) 3.5-3.7 (m, 1H)3.9-4.1 (m, 7H) 4.6-4.8 (m, 2H) 6.2 (s, 1H) 8.4 (s, 1H). MS (ES) MH⁺:438 for C₂₀H₂₄ClN₃O₆.

Intermediate 178S(S)—N-[(1S)-2-[tert-Butyl(dimethyl)silyl]oxy-1-(2-methyl-1,2,4-triazol-3-yl)ethyl]-2-methyl-propane-2-sulfinamide

n-Butyl lithium (185 ml, 462 mmol) was added dropwise at −78° C. undernitrogen to a solution of 1-methyl-1H-[1,2,4]triazole (8 g, 96.43 mmol)in tetrahydrofuran (1000 mL), and the solution was stirred at thistemperature for 30 minutes. A solution of[S(S)]-N-[2-[[(1,1-dimethylethyl)dimethylsilyl]oxy]ethylidene]-2-methyl-2-propanesulfinamide(107 g, 385 mmol) Rech, J. C. et al. JACS (2007), 129(3), 490-491) in1200 mL tetrahydrofuran was added dropwise at −78° C. and stirred for 3hours. The mixture was quenched with saturated aqueous NH₄Cl (200 mL)and extracted with ethyl acetate (1000 ml×3). The combined organiclayers were washed with saturated aqueous NaCl and dried over Na₂SO₄.Solids were filtered off, and the filtrate was concentrated to givecrude material that was purified by silica gel column chromatography(gradient elution with petroleum ether/ethyl acetate from 20/1 to 3/1)to give the title compound (100 g, 72%) as a yellow oil. ¹H NMR (400MHz, CDCl₃) δ 0.00 (s, 3H), 0.04 (s, 3H), 0.85 (s, 3H), 1.3 (s, 9H), 4.0(s, 3H), 4.2-4.6 (m, 2H), 4.7 (m, 1H), 7.9 (s, 1H).

Intermediate 179 (2S)-2-Amino-2-(2-methyl-1,2,4-triazol-3-yl)ethanol

An amount of 2 M of HCl in tert-butyl methyl ether (320 mL) was addedslowly to a solution of Intermediate 178 (70 g, 194 mmol) in MeOH (330mL) at 0° C. The mixture was stirred in cooling bath overnight.Tert-butyl methyl ether (200 mL) was added and the mixture was stirredfor 1 hour. Solids from the mixture was filtered to give the titlecompound as a white solid of the bis-HCl salt (23 g, 87%). ¹H NMR (400MHz, D₂O) δ 3.75 (s, 3H), 3.8 (d, 2H) 4.7 (t, 1H), 7.8 (s, 1H). MS (ES)MH⁺: 143 for C₅H₁₀F₂N₄O.

Intermediate 180(S)-2-(5-(1,3-dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-ylamino)-2-(1-methyl-1H-1,2,4-triazol-5-yl)ethanol

Intermediate 180 was synthesized following the procedure described forthe preparation of Intermediate 17 using Intermediate 179 andIntermediate 16. MS (ES) MH⁺: 368 for C₁₅H₁₅F₂N₅O₄.

Intermediate 181(S)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(1-methyl-1H-1,2,4-triazol-5-yl)oxazolidin-2-one

Intermediate 181 was synthesized following the procedure described forthe preparation of Intermediate 18 using Intermediate 180. ¹H NMR (300MHz, CDCl₃) δ 1.6 (br.s., 4H), 4.0-4.1 (m, 2H), 4.15 (s, 3H), 4.8-5.0(m, 1H), 5.8 (dd, 1H), 7.9 (s, 1H), 8.4 (dd, 1H). MS (ES) MH⁺: 394 forC₁₆H₁₃F₂N₅O₅.

Intermediate 182(S)-6,7-Difluoro-3-(4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 182 was synthesized following the procedure described forthe preparation of Intermediate 19 using Intermediate 181. MS (ES) MH⁺:350 for C₁₄H₉F₂N₂O₄.

Intermediate 1836-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((S)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 183 was synthesized following the procedure described forthe preparation of Intermediate 20 using Intermediate 182. MS (ES) MH⁺:445 for C₂₀H₂₁FN₆O₅.

Intermediate 184S(R)—N-[(1R)-2-[tert-Butyl(dimethyl)silyl]oxy-1-(2-methyl-1,2,4-triazol-3-yl)ethyl]-2-methyl-propane-2-sulfinamide

An amount of n-butyl lithium (38.57 mL, 96.43 mmol) was added dropwiseat −78° C. under nitrogen to a solution of 1-methyl-1H-[1,2,4]triazole(8 g, 96.43 mmol) in tetrahydrofuran (250 ml), and the solution wasstirred at this temperature for 30 minutes. A solution of[S(R)]-N-[2-[[(1,1-dimethylethyl)dimethylsilyl]oxy]ethylidene]-2-methyl-2-propanesulfinamide(22.3 g (80.36 mmol) (Seguin, C. et al. J. Org. Chem. (2009), 74(18),6986-6992) in 20 mL tetrahydrofuran was added dropwise at −78° C. andstirred for 3 hours. The mixture was quenched with saturated aqueousNH₄Cl (40 ml). The above reaction was carried out again in a secondbatch. The two batches after the aqueous NH₄Cl were combined andextracted with ethyl acetate (100 ml×3). The combined organic layerswere washed with saturated aqueous NaCl and dried over Na₂SO₄. Solidswere filtered off, and the filtrate was concentrated to give crudematerial that was purified by silica gel column chromatography (gradientelution with petroleum ether/ethyl acetate from 20/1 to 3/1) to give thetitle compound (31.8 g, 55%) as a yellow oil. ¹H NMR (400 MHz, CDCl₃) δ0.00 (s, 3H), 0.04 (s, 3H), 0.85 (s, 3H), 1.3 (s, 9H), 4.0 (s, 3H),4.2-4.6 (m, 2H), 4.7 (m, 1H), 7.9 (s, 1H).

Intermediate 185 (2R)-2-Amino-2-(2-methyl-1,2,4-triazol-3-yl)ethanol

An amount of 2 M of HCl in tert-butyl methyl ether (210 mL) was addedslowly to a solution of Intermediate 184 (45 g, 135 mmol) in MeOH (210mL) at 0° C. The mixture was stirred in cooling bath overnight.Tert-butyl methyl ether (200 mL) was added and the mixture was stirredfor 1 hour. Solids from the mixture were filtered to give the titlecompound as a white solid of the bis-HCl salt (23 g, 87%). ¹H NMR (400MHz, d4-MeOH) δ 3.9 (d, 2H) 4.0 (s, 3H), 4.8 (t, 1H), 8.0 (s, 1H). MS(ES) MH⁺: 143 for C₅H₁₀F₂N₄O.

Intermediate 186(R)-2-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-ylamino)-2-(1-methyl-1H-1,2,4-triazol-5-yl)ethanol

Intermediate 186 was synthesized following the procedure for thepreparation of Intermediate 17 using Intermediate 185 and Intermediate16. MS (ES) MH⁺: 368 for C₁₅H₁₅F₂N₅O₄.

Intermediate 187(R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(1-methyl-1H-1,2,4-triazol-5-yl)oxazolidin-2-one

Intermediate 187 was synthesized following the procedure for thepreparation of Intermediate 18 using Intermediate 186. ¹H NMR (300 MHz,CDCl₃) δ 1.6 (br.s., 4H), 4.0-4.1 (m, 2H), 4.15 (s, 3H), 4.75-5.0 (m,1H), 5.8 (dd, 1H), 7.9 (s, 1H), 8.4 (dd, 1H). MS (ES) MH⁺: 394 forC₁₆H₁₃F₂N₅O₅.

Intermediate 188(R)-6,7-Difluoro-3-(4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 188 was synthesized following the procedure for thepreparation of Intermediate 19 using Intermediate 187. MS (ES) MH⁺: 350for C₁₄H₉F₂N₂O₄.

Intermediate 1896-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((R)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 189 was synthesized following the procedure for thepreparation of Intermediate 20 using Intermediate 188. MS (ES) MH⁺: 445for C₂₀H₂₁FN₆O₅.

Intermediate 190 (2S,3S)-Methyl2-(((benzyloxy)carbonyl)amino)-3-hydroxybutanoate

To a stirred solution of (2S,3S)-methyl 2-amino-3-hydroxybutanoate (2.5g, 14.73 mmol) in a 1:1 mixture of tetrahydrofuran and water (50 mL),sodium bicarbonate (1.9 g, 22.10 mmol) was added and the mixture wascooled to 0° C. and to this benzyl chloroformate (2.76 g, 16.21 mmol)was added drop wise over a period of 30 minutes. The mixture was thenstirred at the room temperature for 16 hours. The reaction mixture wasdiluted with ethyl acetate (25 mL), organic layers were separated,washed with brine (25 mL) and dried over sodium sulfate. Removal ofsolvents under vacuum afforded the crude product which has been purifiedby silica gel column chromatography (230-400 mesh) using a gradient ofethyl acetate in pet.ether. Yield: 3.4 g (86%) ¹H NMR (400 MHz, DMSO-d₆)δ: 1.09 (d, 3H), 3.89 (s, 3H), 3.99 (t, 1H), 4.01-4.06 (m, 1H), 5.00 (d,1H), 5.04 (s, 2H), 7.30-7.40 (m, 5H), 7.63 (d, 1H). MS (ES) MH⁺: 268.1for C₁₃H₁₇NO₅.

Intermediate 191 (2S,3S)-Methyl2-(((benzyloxy)carbonyl)amino)-3-((tetrahydro-2H-pyran-2-yl)oxy)butanoate

To a stirred solution of Intermediate 190 (2.0 g, 7.89 mmol) indichloromethane (20 mL), pyridinium p-toluene sulfonate (0.79 g, 3.16mmol) and 2,3-dihydropyran (1.02 g, 11.85 mmol) were added at once andthe solution was stirred at the room temperature for 16 hours. Saturatedsodium bicarbonate solution (50 mL) was added to the reaction mixture,the organic layer was separated and the aqueous layer was extracted withdichloromethane (2×50 mL). Combined organic layers were washed withwater (50 mL) and brine solution (50 mL) and dried over sodium sulfate.Removal of solvent afforded the crude product which was purified byflash column chromatography (silica gel: 60-120 mesh) using a gradientof ethyl acetate in pet.ether. Yield: 2.4 g (87%). ¹H NMR (300 MHz,DMSO-d₆) δ: 1.10 & 1.15 (d, 3H), 1.41-1.58 (m, 6H), 3.36-3.43 (m, 1H),3.63 (s, 3H), 3.69-3.73 (m, 1H), 3.99 (q, 1H), 4.15 & 4.27 (t, 1H), 4.57& 4.72 (s, 1H), 5.03 (s, 2H), 7.28-7.34 (m, 5H), 7.71 & 7.79 (d, 1H).

Intermediate 192 Benzyl((2R,3S)-1-hydroxy-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-2-yl)carbamate

To a stirred solution of Intermediate 191 (2.4 g, 7.12 mmol) in a 7:3mixture of tetrahydrofuran and methanol (20 mL), sodium borohydride(0.32 g, 8.55 mmol) was added portion wise at 5° C. and the solution wasstirred at the room temperature for 3 hours. The volatiles were removedunder vacuum and the residue was dissolved in ethyl acetate (50 mL) andwashed with water (25 mL). The aqueous layer was extracted with ethylacetate (2×25 mL). The combined organic layers were washed with brinesolution (25 mL) and dried over sodium sulfate. Removal of solventsafforded the crude product which was taken to the next step withoutfurther purification. Yield: 1.6 g (70%).

Intermediate 193(2R,3S)-2-amino-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-1-ol

To a stirred solution Intermediate 192 (1.6 g, 4.95 mmol) in ethylacetate (20 mL), triethylamine (1 mL) and 10% palladium on charcoal(0.16 g, 10 wt %) was added and the mixture was stirred at the roomtemperature under 20 mm pressure of hydrogen for 6 hours. The mixturewas filtered and the volatiles were removed under vacuum and the crudeproduct was taken to the next step without purification. Yield: 0.93 g(99%).

Intermediate 1945-(1,3-dioxolan-2-yl)-2,3,4-Trifluoro-N′-hydroxy-N-((2R,3S)-1-hydroxy-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-2-yl)benzimidamide

To a stirred solution of Intermediate 194 (0.95 g, 5.02 mmol) indimethyl formamide (10 mL), triethylamine (0.76 g, 7.53 mmol) was addedand the mixture was stirred at the room temperature for 20 minutes.Intermediate 16 (1.41 g, 5.02 mmol) was added and the mixture wasstirred at the room temperature for another 2 hours. The mixture waspoured into ice cold water (50 mL) and extracted with ethyl acetate(3×50 mL). The organic layers were washed with water (2×25 mL), brinesolution (25 mL) and dried over sodium sulfate. Removal of solventafforded the crude product which was purified by silica gel flash columnchromatography using a gradient of ethyl acetate in pet. ether. Thiscompound obtained as a mixture of diastereomers. Yield: 1.0 g (46%) ¹HNMR (400 MHz, DMSO-d₆) δ: 1.01 & 1.09 (d, 3H), 1.16-1.56 (m, 6H),2.77-2.79 & 2.88-2.90 (m, 1H), 3.38-3.78 (m, 5H), 3.99-4.05 (m, 4H),4.43 & 4.56 (s, 1H), 4.66 & 4.74 (t, 1H), 5.69 & 5.80 (d, 1H), 6.03 (s,1H), 7.36-7.38 (m, 1H), 10.00 & 10.09 (s, 1H). ¹⁹F NMR (376.5 MHz,DMSO-d₆) δ: −133.89 (m), −138.56 (m), −159.90 (m). MS (ES) MH⁺: 435.3for C₁₉H₂₅F₃N₂O₆.

Intermediate 195(2R,3S)-2-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-1-ol

To a stirred solution of Intermediate 194 (1.0 g, 2.30 mmol) in dimethylformamide (10 mL), cesium carbonate (1.13 g, 3.45 mmol) was added andthe mixture was stirred at the room temperature for 16 hours. Water (10mL) was added to the mixture and the solution was extracted with ethylacetate (3×25 mL). The organic layers were washed with water (25 mL),brine solution (25 mL) and dried over sodium sulfate. Removal of solventafforded the crude product which was further purified by silica gelflash column chromatography using 75% ethyl acetate in pet.ether. Thiscompound was obtained as a mixture of diastereomers. Yield: 0.60 g(63%). MS (ES) MH⁺: 415.3 for C₁₉H₂₄F₂N₂O₆.

Intermediate 196(4R)-3-(5-(1,3-dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-((1S)-1-((tetrahydro-2H-pyran-2-yl)oxy)ethyl)oxazolidin-2-one

To a stirred solution of Intermediate 195 (0.60 g, 1.45 mmol) inacetonitrile (10 mL), triethylamine (0.5 mL, 3.62 mmol) was added at 0°C. and the mixture was stirred for 15 minutes. To this,bis(2,5-dioxopyrrolidin-1-yl) carbonate (or) disuccinimidyl carbonate(0.93 g, 3.62 mmol) was added at 0° C. and the mixture was stirred atthe room temperature for 16 hours. The volatiles were removed undervacuum and the residue was dissolved in ethyl acetate (10 mL), washedwith water (5 mL), brine solution (5 mL) and dried over sodium sulfate.Removal of solvent under vacuum afforded pale yellow solid which waspurified in a Combi-Flash instrument using a gradient of ethyl acetatein pet.ether. This compound obtained as a mixture of diastereomers.Yield: 0.23 g (36%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.10 & 1.19 (d, 3H),1.22-1.72 (m, 6H), 2.85-2.92 & 3.01-3.12 (m, 1H), 3.65-3.67 (m, 1H),4.00-4.05 (m, 4H), 4.32-4.35 (m, 1H), 4.57-4.65 (m, 4H), 6.09 (s, 1H),8.26 & 8.36 (d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −140.34 & −140.59(d), −160.87 & 161.19 (d).

Intermediate 1976,7-Difluoro-3-((R)-4-((S)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

To a stirred solution of Intermediate 196 (0.23 g, 0.68 mmol) in1,4-dioxane (3 mL), 6N hydrochloric acid (3 mL) was added at 0° C. andthe mixture was stirred at room temperature for 1 hour. The mixture waspoured into ice-cooled water (25 mL) and extracted with ethyl acetate(3×25 mL). The organic layers were washed with water (15 mL), brinesolution (15 mL) and dried over sodium sulfate. Removal of solventafforded the crude product which was taken to the next step withoutpurification. Yield: 0.15 g (92%). MS (ES) MH⁺: 313.1 for C₁₃H₁₀F₂N₂O₅.

Intermediate 1986-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((R)-4-((S)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

To a stirred solution of Intermediate 197 (0.15 g, 0.48 mmol) inacetonitrile (2 mL), was added diisopropyl ethylamine (0.09 g, 0.72mmol) followed by (2R,6R)-2,6-dimethylmorpholine (0.06 g, 0.53 mmol) andthe mixture was heated at 80° C. for 6 hours in a sealed tube. Thesolution was cooled to room temperature and the volatiles were removedunder vacuum to obtain the crude product which was purified in aCombi-Flash instrument using a gradient of ethyl acetate in pet.ether toobtain the title compound as pale yellow solid. Yield: 0.12 g (77%). ¹HNMR (400 MHz, DMSO-d₆) δ: 1.05 (d, 3H), 1.22 (d, 6H), 2.99-3.04 (m, 2H),3.36-3.39 (m, 2H), 4.12-4.15 (m, 2H), 4.31-4.33 (m, 1H), 4.52-4.60 (m,3H), 5.22 (d, 1H), 8.63 (s, 1H), 10.32 (s, 1H). ¹⁹F NMR (376.5 MHz,DMSO-d₆) δ: −146.94 (d). MS (ES) MH⁺: 408.3 for C₁₉H₂₂FN₃O₆.

Intermediate 199[(4R)-3-{6-[(2R,6R)-2,6-dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-2-oxo-1,3-oxazolidin-4-yl]methylmethanesulfonate

To a stirred solution of Intermediate 107 (0.3 g, 0.68 mmol) indichloromethane (5 mL), triethylamine (0.14 mL, 1.02 mmol) andmethanesulfonyl chloride (0.12 g, 1.02 mmol) were added at 0° C.followed by methanesulfonyl chloride (1.63 g, 8.55 mmol). The resultingsolution was stirred at room temperature for a period of an hour. Water(2 mL) was added to the reaction mixture and it was extracted with ethylacetate (2×10 mL). The organic layers were washed with brine solution (5mL), dried over sodium sulfate and solvents were removed under vacuum toobtained crude product which was purified by silica gel flash columnchromatography using a gradient of ethyl acetate in hexane. Yield: 0.25g (71%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.18 (d, 6H), 2.88-2.92 (m, 2H),3.18 (s, 3H), 3.21-3.24 (m, 2H), 3.95-4.01 (m, 2H), 4.04-4.10 (m, 4H),4.46-4.52 (m, 2H), 4.74-4.78 (m, 2H), 4.94-4.95 (m, 1H), 6.17 (s, 1H),8.23 (s, 1H). MS (ES) MH⁺: 516.4 for C₂₁H₂₆FN₃O₉S.

Intermediate 200[(4S)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-7-fluoro-5-formyl-1,2-benzoxazol-3-yl}-2-oxo-1,3-oxazolidin-4-yl]acetonitrile

To a stirred solution of Intermediate 199 (0.28 g, 0.54 mmol) inacetonitrile (5 mL), 1M solution of tetrabutyl ammonium fluoride intetrahydrofuran (0.2 mL, 0.65 mmol) and trimethylsilyl cyanide (0.08 mL,0.65 mmol) were added and the mixture was stirred at the roomtemperature for 2 days. Water (2 mL) was added to the reaction mixtureand it was extracted with ethyl acetate (2×10 mL). The organic layerswere washed with brine solution (5 mL), dried over sodium sulfate andsolvents were removed under vacuum to obtained crude product which waspurified by silica gel flash column chromatography using a gradient ofethyl acetate in hexane. Yield: 0.11 g (50%). ¹H NMR (400 MHz, DMSO-d₆)δ: 1.20 (d, 6H), 2.98-3.04 (m, 2H), 3.14-3.20 (m, 2H), 3.32-3.40 (m,2H), 4.08-4.12 (m, 2H), 4.47-4.51 (m, 1H), 4.81 (t, 1H), 4.90-4.92 (m,1H), 8.56 (s, 1H), 10.30 (s, 1H). MS (ES) MH⁺: 403.4 for C₁₉H₁₉FN₄O₅.

Intermediate 201(R)-4-((R)-1,2-Dihydroxyethyl)-3-(6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)oxazolidin-2-one

To a solution of Intermediate 120 (0.50 g, 1.15 mmol) in a mixture oft-butanol and water (10 mL; 1:1), AD-mix-13 (5.0 g) was added and themixture was stirred at the room temperature for 16 hours. Solid sodiumsulfite (5.0 g) was added to this mixture at 0° C. and it was stirred atroom temperature for an hour. The mixture was extracted with ethylacetate (3×15 mL) and the combined organic layers were washed with water(10 mL), brine (10 mL) and dried over sodium sulfate. Removal of solventunder vacuum afforded solid which was taken to the next step withoutfurther purification. Yield: 0.50 g (93%). ¹HNMR (400 MHz, DMSO-d₆) δ:1.22 (br s, 6H), 2.88-2.92 (m, 2H), 3.20-3.22 (m, 2H), 3.32-3.36 (m,1H), 3.43-3.44 (m, 1H), 3.96-4.01 (m, 2H), 4.03-4.10 (m, 4H), 4.16-4.18(m, 1H), 4.56-4.62 (m, 2H), 4.75-4.76 (m, 1H), 4.86 (t, 1H), 5.36 (d,1H), 6.18 (s, 1H), 8.33 (s, 1H). MS (ES) MH⁺: 468.3 for C₂₁H₂₆FN₃O₈.

Intermediate 202(R)-4-((S)-1,2-Dihydroxyethyl)-3-(6-((2R,6R)-2,6-dimethylmorpholino)-5-(1,3-dioxolan-2-yl)-7-fluorobenzo[d]isoxazol-3-yl)oxazolidin-2-one

Intermediate 202 was synthesized following the procedure described forthe preparation of Intermediate 201 using Intermediate 120 (0.50 g, 1.15mmol) and AD-mix-α (5.0 g). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.23 (br s,6H), 2.87-2.91 (m, 2H), 3.20-3.22 (m, 2H), 3.33-3.36 (m, 1H), 3.43-3.44(m, 1H), 3.96-4.02 (m, 2H), 4.03-4.10 (m, 4H), 4.16-4.17 (m, 1H),4.56-4.64 (m, 2H), 4.75-4.76 (m, 1H), 4.86 (t, 1H), 5.36 (d, 1H), 6.18(s, 1H), 8.33 (s, 1H). MS (ES) MH⁺: 468.3 for C₂₁H₂₆FN₃O₈.

Intermediate 203(5R)-3-{6-[(2R,6R)-2,6-Dimethylmorpholin-4-yl]-5-(1,3-dioxolan-2-yl)-7-fluoro-1,2-benzoxazol-3-yl}-2-oxo-1,3-oxazolidine-5-carbonitrile

A solution of Intermediate 89 (0.38 g, 0.84 mmol) intrichloroacetonitrile (5 mL) was heated at 95° C. for 2 hours. Thevolatiles were evaporated and the crude product was purified by silicagel flash column chromatography using a gradient of 25-30% ethyl acetatein hexane. Yield: 0.13 g (36%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.25 (br s,6H), 2.88-2.92 (m, 2H), 3.22 (d, 2H), 3.96-4.01 (m, 2H), 4.04-4.10 (m,4H), 4.34-4.37 (m, 1H), 4.48 (t, 1H), 5.93 (dd, 1H), 6.17 (s, 1H), 8.35(s, 1H). MS (ES) MH⁺: 433.3 for C₂₀H₂₁FN₄O₆.

Intermediate 204 (2S,3R)-Methyl2-(((benzyloxy)carbonyl)amino)-3-((tetrahydro-2H-pyran-2-yl)oxy)butanoate

To a stirred solution of (2S,3R)-methyl2-(((benzyloxy)carbonyl)amino)-3-hydroxybutanoate (5.0 g, 18.72 mmol) indichloromethane (100 mL), pyridinium p-toluene sulfonate (0.47 g, 1.87mmol) and 2,3-dihydropyran (2.6 mL, 28.08 mmol) were added at once andthe solution was stirred at room temperature for 16 hours. Saturatedsodium bicarbonate solution (50 mL) was added to the reaction mixture,the organic layer was separated and the aqueous layer was extracted withdichloromethane (2×50 mL). The combined organic layers were washed withwater (50 mL) and brine solution (50 mL) and dried over sodium sulfate.Removal of solvent afforded the crude product which was purified byflash column chromatography (silica gel: 60-120 mesh) using a gradientof ethyl acetate in pet.ether. The product was obtained as mixture ofdiastereomers. Yield: 5.9 g (90%). ¹H NMR (400 MHz, DMSO-d₆) δ: 1.10 &1.15 (d, 3H), 1.38-1.72 (m, 6H), 3.39-3.41 (m, 1H), 3.60-3.64 (m, 1H),3.65 (s, 3H), 4.17-4.25 (m, 2H), 4.57 & 4.67 (t, 1H), 5.05 & 5.06 (s,2H), 7.31-7.37 (m, 5H), 7.26 & 7.58 (d, 1H).

Intermediate 205 Benzyl((2R,3R)-1-hydroxy-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-2-yl)carbamate

To a stirred solution of Intermediate 204 (5.90 g, 16.80 mmol) in a 7:3mixture of tetrahydrofuran and methanol (200 mL), sodium borohydride(1.60 g, 42.02 mmol) was added portion wise at 5° C. and the solutionwas stirred at room temperature for 3 hours. Volatiles were removedunder vacuum and the residue was dissolved in ethyl acetate (50 mL),washed with water (25 mL) and the aqueous layer was extracted with ethylacetate (2×25 mL). The combined organic layers were washed with brinesolution (25 mL) and dried over sodium sulfate. Removal of solventsafforded the crude product which has been taken to the next step withoutfurther purification. Yield: 4.9 g (90%). MS (ES) MH⁺: 324.3 forC₁₇H₂₅NO₅

Intermediate 206(2R,3R)-2-Amino-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-1-ol

To a stirred solution of Intermediate 205 (4.9 g, 15.17 mmol) in ethylacetate (50 mL), triethylamine (1 mL) and 10% palladium on charcoal (1.0g, 10 wt %) was added and the mixture was stirred at room temperatureunder 20 mm pressure of hydrogen for 6 hours. The mixture was filteredand the volatiles were removed under vacuum and the crude product hasbeen taken to the next step without purification. Yield: 2.5 g (87%)

Intermediate 2075-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-((2R,3R)-1-hydroxy-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-2-yl)benzimidamide

To a stirred solution of Intermediate 206 (2.5 g, 13.22 mmol) indimethyl formamide (20 mL), triethylamine (2.0 g, 19.84 mmol) was addedand the mixture was stirred at the room temperature for 20 minutes. Tothis, Intermediate 16 (3.1 g, 11.24 mmol) was added and the mixture wasstirred at the room temperature for another 2 hours. The mixture waspoured into ice cold water (50 mL), extracted with ethyl acetate (3×50mL), organic layers were washed with water (2×25 mL), brine solution (25mL) and dried over sodium sulfate. Removal of solvent afforded the crudeproduct which was purified by silica gel flash column chromatographyusing a gradient of ethyl acetate in pet. ether. Yield: 2.2 g (38%). ¹HNMR (400 MHz, DMSO-d₆) δ: 1.08 & 1.12 (d, 3H), 1.44-1.72 (m, 6H),3.65-3.85 (m, 1H), 3.36-3.42 (m, 2H), 3.76-3.78 (m, 2H), 3.96-4.05 (m,5H), 4.57-4.75 (m, 2H), 5.61 (d, 1H), 6.04 (s, 1H), 7.36-7.38 (m, 1H),10.04 & 10.08 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −134.33 (m),−138.45 (m), −159.79 (m). MS (ES) MH⁺: 435.3 for C₁₉H₂₅F₃N₂O₆.

Intermediate 208(2R,3R)-2-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-3-((tetrahydro-2H-pyran-2-yl)oxy)butan-1-ol

To a stirred solution of Intermediate 207 (2.2 g, 5.07 mmol) in dimethylformamide (25 mL), cesium carbonate (3.65 g, 11.19 mmol) was added andthe mixture was stirred at room temperature for 16 hours. Water (10 mL)was added to the mixture, extracted with ethyl acetate (3×25 mL), theorganic layers were washed with water (25 mL), brine solution (25 mL)and dried over sodium sulfate. Removal of solvent afforded the crudeproduct which was further purified by silica gel flash columnchromatography using 75% ethyl acetate in pet.ether. Yield: 1.3 g (62%).¹H NMR (400 MHz, DMSO-d₆) δ: 1.10 & 1.18 (d, 3H), 1.41-1.80 (m, 6H),3.42-3.44 (m, 1H), 3.57-3.60 (m, 2H), 3.61-3.63 (m, 1H), 3.70-3.72 (m,1H), 4.00-4.08 (m, 5H), 4.65-4.77 (m, 2H), 6.07 (s, 1H), 7.09 & 7.11 (d,1H), 8.13 (t, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −143.47 (m), −162.10(m). MS (ES) MH⁺: 415.3 for C₁₉H₂₄F₂N₂O₆.

Intermediate 209(4R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-((1R)-1-((tetrahydro-2H-pyran-2-yl)oxy)ethyl)oxazolidin-2-one

To a stirred solution of Intermediate 208 (0.35 g, 0.84 mmol) inacetonitrile (10 mL), triethylamine (0.17 g, 1.69 mmol) was added at 0°C. and the mixture was stirred for 15 minutes. To this,bis(2,5-dioxopyrrolidin-1-yl)carbonate or disuccinimidyl carbonate (0.23g, 0.89 mmol) was added at 0° C. and the mixture was stirred at the roomtemperature for 16 hours. Volatiles were removed under vacuum and theresidue was dissolved in ethyl acetate (10 mL), washed with water (5mL), brine solution (5 mL) and dried over sodium sulfate. Removal ofsolvent under vacuum afforded pale yellow solid which was purified in aCombi-Flash instrument using a gradient of ethyl acetate in pet.ether.Yield: 0.12 g (32%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.03 & 1.09 (d, 3H),1.22-1.72 (m, 6H), 3.42-3.44 (m, 1H), 3.70-3.85 (m, 1H), 4.00-4.04 (m,4H), 4.35 (t, 1H), 4.55 (t, 1H), 4.62-4.68 (m, 2H), 4.79 (t, 1H), 6.09(s, 1H), 8.25 (d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −140.46 (d),−161.07 (m).

Intermediate 2106,7-Difluoro-3-((R)-4-((R)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

To a stirred solution of Intermediate 209 (0.12 g, 0.27 mmol) in1,4-dioxane (2 mL), 6N hydrochloric acid (2 mL) was added at 0° C. andthe mixture was stirred at the room temperature for 1 hour. The mixturewas poured into ice-cooled water (25 mL) and extracted with ethylacetate (3×25 mL). Organic layers were washed with water (15 mL), brinesolution (15 mL) and dried over sodium sulfate. Removal of solventafforded the title product. Yield: 0.07 g (82%). ¹H NMR (300 MHz,DMSO-d₆) δ: 0.99 (d, 3H), 4.27-4.28 (m, 1H), 4.57-4.66 (m, 3H), 5.28 (d,1H), 8.70 (d, 1H), 10.18 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ:−140.41 (d), −161.03 (d). MS (ES) MH⁺: 313.1 for C₁₃H₁₀F₂N₂O₅.

Intermediate 2116-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((R)-4-((R)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

To a stirred solution of Intermediate 210 (0.07 g, 0.22 mmol) inacetonitrile (2 mL), was added diisopropyl ethylamine (0.04 g, 0.34mmol) followed by (2R,6R)-2,6-dimethylmorpholine (0.03 g, 0.25 mmol) andthe mixture was heated at 80° C. for 6 hours in a sealed tube. Thesolution was cooled to room temperature and the volatiles were removedunder vacuum to obtain the crude product which was purified in aCombi-Flash instrument using a gradient of ethyl acetate in pet.ether toobtain the title compound as pale yellow solid. Yield: 0.07 g (77%). ¹HNMR (300 MHz, DMSO-d₆) δ: 0.98 (d, 3H), 1.20 (d, 6H), 2.99-3.03 (m, 2H),3.35-3.39 (m, 2H), 4.11-4.13 (m, 1H), 4.25-4.35 (m, 1H), 4.57-4.63 (m,4H), 5.25 (d, 1H), 8.55 (s, 1H), 10.30 (s, 1H). ¹⁹F NMR (376.5 MHz,DMSO-d₆) δ: −161.03 (d). MS (ES) MH⁺: 408.3 for C₁₉H₂₂FN₃O₆.

Intermediate 2125-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N-((2R,3R)-1-fluoro-3-hydroxybutan-2-yl)-N′-hydroxybenzimidamide

Intermediate 212 was synthesized following the procedure for thepreparation of Intermediate 207 using (2R,3S)-3-amino-4-fluorobutan-2-ol(0.35 g, 2.48 mmol) (prepared according to the literature procedure;Tet. Lett. 1985, 26, 4687 & WO2005/66119 A2, 2005, column 27-28 andIntermediate 16 (0.84 g, 2.98 mmol). Yield: 0.55 g (83%). ¹H NMR (300MHz, DMSO-d₆) δ: 1.02 (d, 3H), 3.69 (br s, 2H), 3.97-4.00 (m, 4H),4.17-4.44 (m, 3H), 5.76 (d, 1H), 6.03 (s, 1H), 7.29 (t, 1H), 10.18 (s,1H). MS (ES) MH⁺: 353.4 for C₁₄H₁₆F₄N₂O₄.

Intermediate 213(2R,3R)-3-((5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-4-fluorobutan-2-ol

Intermediate 213 was synthesized following the procedure for thepreparation of Intermediate 208 using Intermediate 204 (0.39 g, 1.08mmol). Yield: 0.26 g (73%). MS (ES) MH⁺: 333.4 for C₁₄H₁₅F₃N₂O₄.

Intermediate 214(4R,5R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(fluoromethyl)-5-methyloxazolidin-2-one

Intermediate 214 was synthesized following the procedure for thepreparation of Intermediate 209 using Intermediate 205 0.26 g, 0.78mmol). Yield: 0.07 g (25%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.52 (d, 3H),4.00-4.05 (m, 4H), 4.49 (d, 1H), 4.73 (dd, 1H), 4.86-5.06 (m, 2H), 6.09(s, 1H), 8.30 (d, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −140.27 (d),−161.04 (d), −236.04 (s). MS (ES) MH⁺: 359.3 for C₁₅H₁₃F₃N₂O₅.

Intermediate 2156,7-Difluoro-3-((4R,5R)-4-(fluoromethyl)-5-methyl-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 215 was synthesized following the procedure for thepreparation of Intermediate 210 using Intermediate 206 (0.07 g, 0.20mmol). Yield: 0.06 g (85%). MS (ES) MH⁺: 315.3 for C₁₃H₉F₃N₂O₄.

Intermediate 2166-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((4R,5R)-4-(fluoromethyl)-5-methyl-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 216 was synthesized following the procedure for thepreparation of Intermediate 211 using Intermediate 207 (0.06 g, 0.18mmol). Yield: 0.03 g (33%). ¹H NMR (300 MHz, DMSO-d₆) δ: 1.20 (d, 6H),1.52 (d, 3H), 2.99-3.03 (m, 2H), 4.10-4.12 (m, 3H), 4.49 (d, 2H), 4.73(dd, 1H), 4.87-4.94 (m, 1H), 5.05 (d, 1H), 8.55 (s, 1H), 10.30 (s, 1H).¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −146.81 (s), −236.15 (s).

Intermediate 2175-(1,3-Dioxolan-2-yl)-2,3,4-trifluoro-N′-hydroxy-N-((2S,3R)-3-hydroxy-1-methoxybutan-2-yl)benzimidamide

Intermediate 217 was synthesized following the procedure for thepreparation of Intermediate 207 using(2R,3S)-3-amino-4-methoxybutan-2-ol (0.73 g, 4.70 mmol), preparedaccording to the literature procedure; Tet. Lett. 1985, 26, 4687. (Theamino alcohol was prepared as a mixture of diastereomers in the ratio of1:3) and Intermediate 16 (1.45 g, 5.15 mmol). The product has been takento the next step without further purification. Yield: 1.25 g (73%). MS(ES) MH⁺: 365.4 for C₁₅H₁₉F₃N₂O₅.

Intermediate 218(2R,3S)-3-((5-(1,3-dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)amino)-4-methoxybutan-2-ol

Intermediate 218 was synthesized following the procedure described forthe preparation of Intermediate 208 using Intermediate 217 (1.25 g, 3.43mmol). The product was taken to the next step without furtherpurification. Yield: 0.60 g (51%). MS (ES) MH⁺: 345.4 for C₁₅H₁₈F₂N₂O₅.

Intermediate 219(4S,5R)-3-(5-(1,3-Dioxolan-2-yl)-6,7-difluorobenzo[d]isoxazol-3-yl)-4-(methoxymethyl)-5-methyloxazolidin-2-one

Intermediate 219 was synthesized following the procedure described forthe preparation of Intermediate 209 using Intermediate 218 (0.50 g, 1.45mmol). The product has been taken to the next step without furtherpurification. Yield: 0.33 g (61%). MS (ES) MH⁺: 371.4 for C₁₆H₁₆F₂N₂O₆.

Intermediate 2206,7-Difluoro-3-((4S,5R)-4-(methoxymethyl)-5-methyl-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 220 was synthesized following the procedure described forthe preparation of Intermediate 210 using Intermediate 219 (0.33 g, 0.89mmol) and the product has been taken to the next step without furtherpurification. Yield: 0.28 g (96%). MS (ES) MH⁺: 327.4 for C₁₄H₁₂F₂N₂O₅.

Intermediate 2216-((2R,6R)-2,6-Dimethylmorpholino)-7-fluoro-3-((4S,5R)-4-(methoxymethyl)-5-methyl-2-oxooxazolidin-3-yl)benzo[d]isoxazole-5-carbaldehyde

Intermediate 221 was synthesized following the procedure described forthe preparation of Intermediate 211 using Intermediate 220 (0.38 g, 0.86mmol). The product has been taken to the next step without furtherpurification. Yield: 0.28 g (77%). MS (ES) MH⁺: 422.5 for C₂₀H₂₄FN₃O₆.

EXAMPLES Example 1(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-(2-oxo-1,3-oxazolidin-3-yl)-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

A mixture of Intermediate 17 (0.04 g, 0.1 mmol) and barbituric acid(0.01 g, 0.1 mmol) in acetic acid (3 ml) was heated at 110° C. for 2hours. The solvents were evaporated and the residue was dissolved inmethanol (1 mL). Water (3 mL) was added to precipitate solids that werefiltered and purified by reverse phase HPLC (10 mM ammonium acetate inwater, CH₃CN) to afford the title compound as part of a racemic mixturein the form of a solid. Yield: 15 mg (35%). ¹H NMR (400 MHz, DMSO-d₆) δ:0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.7 (t, 2H), 3.8 (m,1H), 3.9 (d, 1H), 4.1 (m, 3H), 4.6 (t, 2H), 7.75 (s, 1H), 11.5 (s, 1H),11.8 (s, 1H). MS (ES) MH⁺: 474.4 for C₂₁H₂₀FN₅O₇.

Alternative Synthesis of Example 1

Intermediate 6 (800 mg, 1.95 mmol) and pyrimidine-2,4,6(1H,3H,5H)-trione(250 mg, 1.95 mmol) in a mixture of acetic acid (8 mL) and water (2 mL)was heated at 110° C. for 3.5 hours. The solvent was removed and thereaction mixture was purified using Super Critical Fluid Chromatography(Chiralpak IA column with 40% isopropanol and 60% CO₂ mobile phase) togive the title compound (571 mg, 61.7% yield) as a solid as the firsteluting compound. ¹H NMR (300 MHz, DMSO-d₆) δ 0.9 (d, 3H) 1.1 (d, 3H)2.8-3.2 (m, 2H) 7.7 (s, 1H) 11.4 (s, 1H) 11.8 (s, 1H). MS (ES) MH⁺: 474for C₂₁H₂₀FN₅O₇.

Also isolated from the synthesis of Alternative Synthesis of Example 1as the second component eluting from the HPLC purification was(2R,4R,4aR)-11-fluoro-2,4-dimethyl-8-(2-oxo-1,3-oxazolidin-3-yl)-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione(40 mg):

¹H NMR (300 MHz, DMSO-d₆) δ 0.95 (d, 3H), 1.3 (d, 3H), 3.1 (d, 1H),3.45-4.3 (m, 8H), 4.5-4.7 (m, 2H), 7.75 (s, 1H), 11.45 (br. s., 1H),11.7 (br. s., 1H). MS (ES) MH⁺: 474 for C₂₁H₂₀FN₅O₇.

Example 2(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

A stirred mixture of Intermediate 8 (0.15 g, 0.36 mmol) and barbituricacid (0.04 g, 0.3 mmol) in acetic acid (1 ml) was heated at 85° C. for16 hours. The solvents were evaporated, the residue was dissolved inmethanol (2 ml) and water (5 ml) was added. The precipitated solids werefiltered and purified by reverse phase HPLC (10 mM ammonium acetate inwater, CH₃CN), eluting two components. The second eluting component wasisolated as a solid and identified as the title compound. Yield: 35 mg(21%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.3 (d, 3H), 1.4 (d,3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.6-3.65 (m, 2H), 3.8 (m, 1H), 3.9 (d,1H), 4.1 (d, 1H), 4.2 (q, 1H), 4.6-4.7 (m, 2H), 7.6 (s, 1H), 11.5 (s,1H), 11.8 (s, 1H). MS (ES) MH⁺: 488.4 for C₂₂H₂₂FN₅O₇: [α]_(D) ²⁰=−239(c=1; MeOH).

Also isolated from the synthesis of Example 2 as the first componenteluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(4R)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

Yield: 20 mg (12%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.3 (d,3H), 1.4 (d, 3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.6 (m, 2H), 3.75 (m, 1H),3.9 (d, 1H), 4.1 (d, 1H), 4.2 (q, 1H), 4.6-4.7 (m, 2H), 7.6 (s, 1H),11.45 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 488.4 for C₂₂H₂₂FN₅O₇ [α]_(D)²⁰=+73 (c=1; MeOH).

Examples 3 to 34 were prepared from barbituric acid and the indicatedstarting material using the method described (with any variation noted)for the synthesis of Example 2, unless otherwise noted.

Example 3(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5S)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 3 was prepared from Intermediate 9. The title compound wasobtained as the second eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 1.45 (d, 3H), 2.9(d, 1H), 3.1 (t, 1H), 3.65-3.7 (m, 2H), 3.75 (m, 2H), 3.9 (d, 1H), 4.1(d, 1H), 4.2 (t, 1H), 4.95 (h, 1H), 7.7 (s, 1H), 11.4 (s, 1H), 11.8 (s,1H). MS (ES) MH⁺: 488.4 for C₂₂H₂₂FN₅O₇; [α]_(D) ²⁰=−130 (c=1; MeOH).

Also isolated from the synthesis of Example 3 as the first componenteluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(5S)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 1.45 (d, 3H), 2.9(d, 1H), 3.10 (t, 1H), 3.65 (m, 2H), 3.7 (m, 2H), 3.9 (d, 1H), 4.1 (d,1H), 4.2 (t, 1H), 4.95 (h, 1H), 7.75 (s, 1H), 11.4 (s, 1H), 11.8 (s,1H). MS (ES) MH⁺: 488.4 for C₂₂H₂₂FN₅O₇; [α]_(D) ²⁰=+101 (c=1; MeOH).

Example 4(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5R)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 4 was prepared from Intermediate 10. The title compound wasobtained as the first eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 1.45 (d, 3H), 2.9(d, 1H), 3.1 (t, 1H), 3.65 (m, 2H), 3.7-3.8 (m, 2H), 3.9 (d, 1H), 4.1(d, 1H), 4.2 (t, 1H), 4.95 (h, 1H), 7.75 (s, 1H), 11.45 (s, 1H), 11.8(s, 1H). MS (ES) MH⁺: 488.4 for C₂₂H₂₂FN₅O₇; [α]_(D) ²⁰=−188 (c=1;MeOH).

Also isolated from the synthesis of Example 4 as the second componenteluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(5R)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 1.45 (d, 3H), 2.9(d, 1H), 3.1 (t, 1H), 3.65 (m, 2H), 3.7-3.8 (m, 2H), 3.9 (d, 1H), 4.1(d, 1H), 4.2 (t, 1H), 4.95 (h, 1H), 7.7 (s, 1H), 11.4 (s, 1H), 11.8 (s,1H). MS (ES) MH⁺: 488.4 for C₂₂H₂₂FN₅O₇.[α]_(D) ²⁰=+179 (c=1; MeOH).

Alternative Syntheses for Example 4 First Alternative Synthesis

Intermediate 12 (1.67 g, 3.96 mmol) andpyrimidine-2,4,6(1H,3H,5H)-trione (0.508 g, 3.96 mmol) in a mixture ofacetic acid (8 mL) and water (2 mL) was heated at 110° C. for 2 hours.The solvent was removed and the reaction mixture was purified by SuperCritical Fluid Chromatography (Chiralpak IA column with 30% isopropanoland 70% CO₂ mobile phase) to give the title compound (1.560 g, 81%) as asolid as the first eluting component. ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9(d, 3H), 1.1 (d, 3H), 1.45 (d, 3H), 2.8-3.2 (m, 2H), 3.6-4.3 (m, 7H),4.9-5.1 (m, 1H), 7.75 (s, 1H), 11.4 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺:488 for C₂₂H₂₂FN₅O₇.

Also isolated from the synthesis of Example 4 (First AlternativeSynthesis) as the second component eluting from the HPLC purificationwas(2R,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(5R)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trion:

¹H NMR (300 MHz, DMSO-d₆) δ: 0.95 (d, 3H), 1.3 (d, 3H), 1.5 (d, 3H), 3.1(d, 1H), 3.5-4.3 (m, 8H), 4.8-5.1 (m, 1H), 7.75 (s, 1H), 11.5 (br. s.,2H). MS (ES) MH⁺: 488 for C₂₂H₂₂FN₅O₇.

Example 4 Second Alternative Synthesis

Intermediate 20 (64 mg, 0.17 mmol) and pyrimidine-2,4,6(1H,3H,5H)-trione(25 mg, 0.20 mmol) in 3 mL of ethanol was heated at 120° C. for 2 hours.Solvent was removed and the reaction mixture was purified by SuperCritical Fluid Chromatography (Chiralpak IA column with 30% isopropanoland 70% CO₂ mobile phase) to give the title compound as a solid as thefirst eluting component. ¹H NMR (300 MHz, DMSO-d₆) δ 0.9 (d, 3H), 1.1(d, 3H), 1.45 (d, 3H), 2.8-3.2 (m, 2H), 3.6-4.3 (m, 7H), 4.9-5.1 (m,1H), 7.75 (s, 1H), 11.4 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 488 forC₂₂H₂₂FN₅O₇.

Example 5(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 5 was prepared from Intermediate 21. The title compound wasisolated by reverse phase HPLC (10 mM ammonium acetate in water, CH3CN)as the first eluting of two components. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.9(d, 3H), 1.15 (d, 3H), 1.4 (d, 3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.5-3.6(m, 2H), 3.8 (m, 1H), 3.9 (d, 1H), 4.0 (d, 1H), 4.2 (q, 1H), 4.6-4.7 (m,2H), 7.6 (s, 1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 488.4 forC₂₂H₂₂FN₅O₇; [α]_(D) ²⁰=−92 (c=1; MeOH).

Also isolated from the synthesis of Example 5 as the second elutingcomponent from HPLC purification was(2S,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(4S)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.15 (d, 3H), 1.4 (d, 3H), 2.9(d, 1H), 3.1 (t, 1H), 3.6-3.7 (m, 2H), 3.8-4.0 (m, 1H), 3.9 (d, 1H), 4.1(d, 1H), 4.2 (q, 1H), 4.6-4.7 (m, 2H), 7.6 (s, 1H), 11.5 (s, 1H), 11.8(s, 1H). MS (ES) MH⁺: 488.4 for C₂₂H₂₂FN₅O₇; [α]_(D) ²⁰=+224 (c=1;MeOH).

Alternative Synthesis of Example 5

A solution of Intermediate 22 (1.14 g, 2.71 mmol) andpyrimidine-2,4,6(1H,3H,5H)-trione (0.346 g, 2.71 mmol) in acetic acid (8mL) and of water (2 mL) was heated at 110° C. for 2 hours. The solventwas removed and the reaction mixture was purified using Super CriticalFluid Chromatography (Chiralpak IC column with 30% methanol and 70% CO₂mobile phase). The first eluting compound was further purified bydissolving in acetonitrile (30 mL) and diluting with water (60 mL) togive the title compound as a solid. (0.910 g, 69.0% yield). ¹H NMR (300MHz, DMSO-d₆) δ: δ0.9 (d, 3H), 1.15 (d, 3H), 1.4 (d, 3H), 2.9 (d, 1H),3.1 (t, 1H), 3.6-3.7 (m, 2H), 3.8 (m, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.2(q, 1H), 4.6-4.75 (m, 2H), 7.6 (s, 1H), 11.4 (s, 1H), 11.8 (s, 1H). MS(ES) MH⁺: 488 for C₂₂H₂₂FN₅O₇.

Also isolated from the synthesis of Alternative Synthesis of Example 5as the second component eluting from the HPLC purification was(2R,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(4S)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (300 MHz, DMSO-d₆) δ: 1.0 (d, 3H), 1.3 (d, 3H), 1.4 (d, 3H), 3.1(d, 1H), 3.5-4.3 (m, 7H), 4.5-4.8 (m, 2H), 7.6 (s, 1H), 11.5 (br. s.,1H), 11.7 (br. s., 1H). MS (ES) MH⁺: 488 for C₂₂H₂₂FN₅O₇.

Example 6(2R,4S,4aS)-8-[(4S)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 6 was prepared from Intermediate 23. The title compound wasobtained as the first eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.8 (t, 3H), 0.9 (d, 3H), 1.1 (d, 3H),1.75-1.9 (m, 2H), 2.90 (d, 1H), 1.8 (t, 1H), 3.5 (m, 1H), 3.65-3.7 (m,1H), 3.8-4.0 (m, 1H), 3.9 (d, 1H), 419 (d, 1H), 4.3-4.3 (m, 1H), 4.55(m, 1H), 4.6-4.7 (m, 1H), 7.6 (s, 1H). MS (ES) MH⁺: 502.4 forC₂₃H₂₄FN₅O₇; [α]_(D) ²⁰=−24 (c=1; MeOH).

Also isolated from the synthesis of Example 6 as the second componenteluting from the HPLC purification was(2S,4R,4aR)-8-[(4S)-4-ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.8 (t, 3H), 0.9 (d, 3H), 1.1 (d, 3H), 1.8(m, 2H), 2.9 (d, 1H), 3.1 (t, 1H), 3.5-3.6 (m, 1H), 3.6-3.7 (m, 1H), 3.7(m, 1H), 3.8 (m, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.3-4.35 (m, 1H),4.5-4.6 (m, 1H), 7.6 (s, 1H). MS (ES) MH⁺: 502.4 for C₂₃H₂₄FN₅O₇;[α]_(D) ²⁰=+101 (c=1; MeOH).

Example 7(2R,4S,4aS)-8-[(4R)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione)

Example 7 was prepared from Intermediate 24. The title compound wasobtained as the second eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.8 (t, 3H), 0.9 (d, 3H), 1.15 (d, 3H),1.8-1.85 (m, 2H), 2.9 (d, 1H), 3.1 (t, 1H), 3.65 (m, 2H), 3.8 (m, 1H),3.9 (d, 1H), 4.1 (d, 1H), 4.3-4.4 (m, 1H), 4.5-4.6 (m, 1H), 4.6-4.7 (m,1H), 7.6 (s, 1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 502.4 forC₂₃H₂₄FN₅O₇; [α]_(D) ²⁰=+101 (c=1; MeOH).

Also isolated from the synthesis of Example 7 as the first componenteluting from the HPLC purification was(2S,4R,4aR)-8-[(4R)-4-ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.8 (t, 3H), 0.9 (d, 3H), 1.15 (d, 3H),1.8-1.9 (m, 2H), 2.9 (d, 1H), 3.1 (t, 1H), 3.6-3.7 (m, 2H), 3.8 (m, 1H),3.9 (d, 1H), 4.1 (d, 1H), 4.3-4.35 (m, 1H), 4.6 (m, 1H), 4.65-4.7 (m,1H), 7.6 (s, 1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 502.4 forC₂₃H₂₄FN₅O₇; [α]_(D) ²⁰=+59 (c=1; MeOH).

Example 8(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 8 was prepared from Intermediate 25. The title compound wasobtained as the second eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1 (t,1H), 3.6-3.7 (m, 2H), 3.8 (m, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.3 (q,1H), 5.0 (t, 1H), 5.7 (q, 1H), 7.2-7.4 (m, 5H), 7.65 (s, 1H), 11.6 (brs, 2H). MS (ES) MH⁺: 550.5 for C₂₇H₂₄FN₅O₇; [α]_(D) ²⁰=−125 (c=0.1;MeOH).

Also isolated from the synthesis of Example 8 as the first componenteluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(4R)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1(t, 1H), 3.6-3.7 (m, 2H), 3.7-3.8 (m, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.3(q, 1H), 5.0 (t, 1H), 5.7 (q, 1H), 7.3-7.4 (m, 5H), 7.65 (s, 1H), 11.5(br s, 1H), 11.9 (br s, 1H). MS (ES) MH⁺: 550.5 for C₂₇H₂₄FN₅O₇; [α]_(D)²⁰=+249 (c=0.1; MeOH).

Example 9(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 9 was prepared from Intermediate 26. The title compound wasobtained as the first eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.95 (d, 1H), 3.1(t, 1H), 3.6 (m, 2H), 3.65-3.7 (m, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.35(q, 1H), 5.0 (t, 1H), 5.7 (q, 1H), 7.3-7.65 (m, 5H), 7.65 (s, 1H), 11.5(s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 550.5 for C₂₇H₂₄FN₅O₇; [α]_(D)²⁰=−228 (c=1; MeOH).

Also isolated from the synthesis of Example 9 as the second componenteluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-2,4-dimethyl-8-[(4S)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1(t, 1H), 3.6-3.7 (m, 2H), 3.75 (m, 1H), 3.9 (d, 1H), 4.05 (d, 1H), 4.3(q, 1H), 5.0 (t, 1H), 5.7 (q, 1H), 7.3-7.4 (m, 5H), 7.7 (s, 1H), 11.5(s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 550.5 for C₂₇H₂₄FN₅O₇; [α]_(D)²⁰=+151 (c=1; MeOH).

Example 10(2R,4S,4aS)-8-[(4R)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 10 was prepared from Intermediate 27. The title compound wasobtained as the second eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1-3.2(m, 3H), 3.6-3.7 (m, 2H), 3.8 (m, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.3-4.4(m, 1H), 4.5 (t, 1H), 4.8 (m, 1H), 7.2 (m, 2H), 7.2-7.3 (m, 3H), 7.6 (s,1H), 11.65 (br s, 2H). MS (ES) MH⁺: 564.5 for C₂₈H₂₆FN₅O₇; [α]_(D)²⁰=−274 (c=0.1; MeOH).

Also isolated from the synthesis of Example 10 as the first componenteluting from the HPLC purification was(2S,4R,4aR)-8-[(4R)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H),3.05-3.1 (m, 2H), 3.1-3.2 (m, 1H), 3.6-3.7 (m, 2H), 3.8 (m, 1H), 3.95(d, 1H), 4.1 (d, 1H), 4.4 (dd, 1H), 4.5 (t, 1H), 4.8 (m, 1H), 7.2 (m,2H), 7.2-7.3 (m, 3H), 7.6 (s, 1H), 11.7 (br s, 2H). MS (ES) MH⁻: 562.4for C₂₈H₂₆FN₅O₇; [α]_(D) ²⁰=+224 (c=0.1; MeOH).

Example 11(2R,4S,4aS)-8-[(4S)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 11 was prepared from Intermediate 28. The title compound wasobtained as the first eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H),3.1-3.15 (m, 2H), 3.2 (m, 1H), 3.6-3.7 (m, 2H), 3.8 (m, 1H), 3.9 (d,1H), 4.1 (d, 1H), 4.4 (dd, 1H), 4.5 (t, 1H), 4.8 (m, 1H), 7.2 (m, 2H),7.2-7.3 (m, 3H), 7.6 (s, 1H), 11.45 (br s, 1H), 11.85 (br s, 1H). MS(ES) MH⁺: 564.5 for C₂₈H₂₆FN₅O₇; [α]_(D) ²⁰=−115 (c=0.1; MeOH).

Also isolated from the synthesis of Example 11 as the second componenteluting from the HPLC purification was(2S,4R,4aR)-8-[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H),3.1-3.2 (m, 3H), 3.6-3.7 (m, 2H), 3.8 (m, 1H), 3.9 (d, 1H), 4.1 (d, 1H),4.4 (dd, 1H), 4.55 (t, 1H), 4.8 (m, 1H), 7.2-7.3 (m, 5H), 7.6 (s, 1H),11.6 (br s, 2H). MS (ES) MH⁺: 564.5 for C₂₈H₂₆FN₅O₇; [α]_(D) ²⁰=+163(c=0.1; MeOH).

Example 12(2R,4S,4aS)-8-(5,5-Dimethyl-2-oxo-1,3-oxazolidin-3-yl)-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 12 was prepared from Intermediate 29. The title compound wasobtained as part of a racemic mixture. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.9(d, 3H), 1.1 (d, 3H), 1.5 (s, 6H), 2.9 (d, 1H), 3.1 (t, 1H), 3.65-3.7(m, 2H), 3.8 (m, 1H), 3.9-3.95 (m, 3H), 4.1 (d, 1H), 7.8 (s, 1H), 11.5(s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 502.4 for C₂₃H₂₄FN₅O₇.

Example 13(2R,4S,4aS)-8-[(5S)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 13 was prepared from Intermediate 31. For the reaction, 100%acetic acid was used with heating for 3 hours at 90° C. ¹H NMR (400 MHz,DMSO-d₆) δ: 0.9 (d, 3H), 1.0 (t, 3H), 1.1 (d, 3H), 1.8 (q, 2H), 2.9 (d,1H), 3.1 (t, 1H), 3.6-3.7 (m, 2H), 3.7-3.8 (m, 2H), 3.9 (d, 1H), 4.1 (d,1H), 4.2 (t, 1H), 4.8 (q, 1H), 7.8 (s, H), 11.5 (s, H), 11.8 (s, H).

Example 14(2R,4S,4aS)-8-[(5R)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 14 was prepared from Intermediate 30. ¹H NMR (400 MHz, DMSO-d₆)δ: 0.9 (d, 3H), 1.0 (t, 3H), 1.1 (d, 3H), 1.8 (q, 2H), 2.9 (d, 1H), 3.1(t, 1H), 3.6-3.7 (m, 2H), 3.8 (m, 2H), 3.9 (d, 1H), 4.1 (d, 1H), 4.2 (t,1H), 4.8 (q, 1H), 7.7 (s, 1H), 11.45 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺:502.4 for C₂₃H₂₄FN₅O₇; [α]_(D) ²⁰=−177 (c=1; MeOH).

Example 15(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 15 was prepared from Intermediate 35. The title compound wasobtained as the first eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1 (t,1H), 3.9 (d, 1H), 3.65-3.7 (m, 1H), 3.75-3.8 (m, 1H), 3.9 (d, 1H), 4.1(d, 1H), 4.5 (dd, 1H), 4.6 (d, 1H), 4.7 (m, 1H), 4.9 (m, 2H), 7.6 (s,1H), 11.0 (br s, 2H). MS (ES) MH⁺: 506.5 for C₂₂H₂₁F₂N₅O₇; [α]_(D)²⁰=−74.4 (c=1.12; MeOH), R_(T)=14.08 min.

Also isolated from the synthesis of Example 15 as the second componenteluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-8-[(4R)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1(t, 1H), 3.6 (d, 1H), 3.65-3.7 m, 1H), 3.75-3.8 (m, 1H), 3.9 (d, 1H),4.1 (d, 1H), 4.5 (dd, 1H), 4.59 (d, 1H), 4.70 (m, 1H), 4.9 (m, 2H), 7.6(s, 1H), 11.0 (br s, 2H). MS (ES) MH⁺: 506.5 for C₂₂H₂₁F₂N₅O₇; [α]_(D)²⁰=+210 (c=1.08; MeOH); R_(T)=14.78 min.

Example 16(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 16 was prepared from Intermediate 36. The title compound wasobtained as the second eluting component from the HPLC purification. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1 (t,1H), 3.6 (d, 1H), 3.65-3.7 (m, 1H), 3.75-3.8 (m, 1H), 3.9 (d, 1H), 4.1(d, 1H), 4.5 (dd, 1H), 4.6 (d, 1H), 4.70 (m, 1H), 4.9 (m, 2H), 7.6 (s,1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 506.5 for C₂₂H₂₁F₂N₅O₇;[α]_(D) ²⁰=−38.6 (c=1.08; MeOH), R_(T)=21.50 min.

Also isolated from the synthesis of Example 16 as the first componenteluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-8-[(4S)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1(t, 1H), 3.6 (d, 1H), 3.65-3.7 (m, 1H), 3.75-38 (m, 1H), 3.9 (d, 1H),4.1 (d, 1H), 4.5 (dd, 1H), 4.6 (d, 1H), 4.70 (m, 1H), 4.9 (m, 2H), 7.6(s, 1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 506.5 forC₂₂H₂₁F₂N₅O₇; [α]_(D) ²⁰=+64.9 (c=1.07; MeOH): R_(T)=17.62 min.

Examples 17 and 18(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trioneand(2R,4S,4aS)-11-fluoro-8-[(4R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

The starting material was a mixture of Intermediate 37 and Intermediate38. The reaction of the starting material according to the indicatedprocedure produced the two diastereomers depicted above, along with eachdiastereomer's corresponding enantiomer. The two diastereomers wereseparated via HPLC. Each diastereomer was obtained along with itscorresponding enantiomer. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.15(d, 3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.2 (s, 3H), 3.5-3.55 (m, 1H),3.65-3.7 (m, 2H), 3.8-3.9 (m, 2H), 3.9 (d, 1H), 4.1 (d, 1H), 4.45-4.5(m, 1H), 4.6-4.65 (m, 2H), 7.7 (s, 1H), 11.5 (br s, 1H), 11.8 (br s,1H). MS (ES) MH⁺: 518.4 for C₂₃H₂₄FN₅O₈.

The diastereomers from the mixture of Examples 17 and 18 were separatedusing Super Critical Fluid Chromatography (Chiralpak IA column with 20%methanol and 80% CO₂ mobile phase). Four components were separated.

Example 17(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

The title compound was obtained as the first eluting component from theHPLC purification. ¹HNMR (300 MHz, DMSO-d⁶) δ: 0.9 (s, 3H), 1.1 (s, 3H),2.9 (d, 1H), 3.1 (t, 1H), 3.25 (s, 3H), 3.5 (d, 1H), 3.6-3.7 (m, 2H),3.7-3.9 (m, 2H), 3.9 (d, 1H), 4.1 (d, 1H), 4.4 (m, 1H), 4.6-4.7 (m, 2H),7.65 (s, 1H), 11.5 (br s, 2H). Optical Rotation: [α]_(D) ²⁰=−128; MS(ES) MH⁺: 518 for C₂₃H₂₄FN₅O₈.

Example 18(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

The title compound was obtained as the fourth eluting component from theHPLC purification. ¹H NMR (300 MHz, DMSO-d⁶) δ: 0.9 (s, 3H), 1.1 (s,3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.2 (s, 3H), 3.5-3.7 (m, 3H), 3.7-3.9 (m,2H), 3.9 (d, 1H), 4.1 (d, 1H), 4.4 (m, 1H), 4.6-4.7 (m, 2H), 7.1 (s,1H), 11.5 (br s, 2H). Optical Rotation: [α]_(D) ²⁰=−189: MS (ES) MH⁺:518 for C₂₃H₂₄FN₅O₈.

Also isolated from the synthesis of Examples 17 and 18 as the secondcomponent eluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-8-[(4R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹HNMR (300 MHz, DMSO-d⁶) δ: 0.88 (s, 3H), 1.1 (s, 3H), 2.9 (d, 1H), 3.1(t, 1H), 3.25 (s, 3H), 3.5-3.7 (m, 3H), 3.7-3.9 (m, 2H), 3.9 (d, 1H),4.1 (d, 1H), 4.4 (m, 1H), 4.6-4.7 (m, 2H), 7.6 (s, 1H), 11.55 (br s,2H). Optical Rotation: [α]_(D) ²⁰=+135; MS (ES) MH⁺: 518 forC₂₃H₂₄FN₅O₈.

Also isolated from the synthesis of Examples 17 and 18 as the thirdcomponent eluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹HNMR (300 MHz, DMSO-d⁶) δ: 0.9 (s, 3H), 1.1 (s, 3H), 2.1 (d, 1H), 3.1(t, 1H), 3.2 (s, 3H), 3.5-3.7 (m, 3H), 3.7-3.9 (m, 2H), 3.9 (d, 1H), 4.1(d, 1H), 4.4 (m, 1H), 4.6-4.7 (m, 2H), 7.1 (s, 1H), 11.6 (br s, 2H).Optical Rotation: [α]_(D) ²⁰=+208; MS (ES) MH⁺: 518 for C₂₃H₂₄FN₅O₈.

Alternative Synthesis of Example 17

A stirred solution of Intermediate 40 (0.67 g, 1.5 mmol) and barbituricacid (0.21 g, 1.6 mmol) in acetic acid (10 mL) was heated to 95° C. for4 hours. The solvents were evaporated and the residue was dissolved inmethanol (2 mL). Water (5 mL) was added to precipitate solids that werecollected and chromatographed by chiral HPLC [Chiralpak IC (250×4.6) mm;hexane:ethanol (80:20); 1.0 ml/min] to separate the title compound asthe second eluting component. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H),1.1 (d, 3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.25 (s, 3H), 3.5 (d, 1H),3.6-3.7 (m, 2H), 3.85 (m, 1H), 3.85-3.9 (d, 1H), 3.9 (d, 1H), 4.1 (d,1H), 4.45-4.5 (m, 1H), 4.6-4.7 (m, 2H), 7.65 (s, 1H), 11.5 (s, 1H), 11.8(s, 1H). MS (ES) MH⁺: 518.4 for C₂₃H₂₄FN₅O₈; [o]_(D) ²⁰=−93.8 (c=1.14;MeOH), R_(T)=20.7 min.

Also isolated from the synthesis of Example 17 (Alternative Synthesis)as the first component eluting from the HPLC purification was(2S,4R,4aR)-11-fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione:

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1(t, 1H), 3.2 (s, 3H), 3.5 (d, 1H), 3.6-3.7 (m, 2H), 3.85 (m, 1H),3.85-3.9 (d, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.45-4.5 (m, 1H), 4.6-4.65(m, 2H), 7.7 (s, 1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 518.4 forC₂₃H₂₄FN₅O₈; [α]_(D) ²⁰=+159.4 (c=1.04; MeOH), R_(T)=17.8 min.

Example 19(2R,4S,4aS)-11-Fluoro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 19 was prepared from Intermediate 44. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column, 80% CO₂, 20% isopropanol) toisolate the major eluting component. ¹H NMR (300 MHz, DMSO-d6) δ: 0.9(d, 3H) 1.1 (d, 3H) 2.8-3.2 (m, 2H) 3.6-4.0 (m, 5H) 4.0-4.3 (m, 2H)4.6-5.2 (m, 3H) 7.75 (s, 1H) 11.4 (s, 1H) 11.8 (s, 1H). MS (ES) MH⁺: 506for C₂₂H₂₁F₂N₅O₇.

Example 20(2R,4S,4aS)-11-Chloro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 20 was prepared from Intermediate 53. The title compound wasobtained as the major eluting component from reverse phase HPLC (20-50%acetonitrile/water gradient with 0.1% TFA) purification. ¹H NMR (300MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.2 (d, 3H), 2.8-3.2 (m, 2H), 3.3 (d, 6H),3.5-3.75 (m, 3H), 3.75-4.1 (m, 3H), 4.2 (t, 1H), 4.5 (d, 1H) 4.8-5.3 (m,1H), 7.85 (s, 1H), 11.4 (br. s, 1H), 11.8 (br s., 1H). MS (ES) MH⁺: 534for C₂₃H₂₄ClN₅O₈.

Example 21(2R,4S,4aS)-11-Chloro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

The starting material was Intermediate 54. The title compound wasobtained as the major eluting component from reverse phase HPLC (20-50%acetonitrile/water gradient with 0.1% TFA) purification. ¹H NMR (300MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.2 (d, 3H), 2.9-3.2 (m, 2H), 3.2-3.45 (m,6H), 3.5-3.75 (m, 3H), 3.8-4.1 (m, 3H), 4.15 (t, 1H), 4.35-4.6 (m, 1H),4.85-5.1 (m, 1H), 7.85 (s, 1H). MS (ES) MH⁺: 534 for C₂₃H₂₄ClN₅O₈.

Example 22((2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((R)-5-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 22 was prepared from Intermediate 55. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column, 60% CO₂, 40% MeOH). ¹H NMR (300MHz, DMSO-d₆) δ: 0.9 (d, 3H) 1.2 (d, 3H) 1.45 (d, 3H) 2.9-3.1 (m, 2H)3.6-3.8 (m, 3H) 3.9-4.05 (m, 2H) 4.2 (dd, 1H) 4.5 (d, 1H) 7.85 (s, 1H)11.4 (s, 1H) 11.8 (s, 1H). MS (ES) MH⁺: 504 for C₂₂H₂₂ClN₅O₇.

Example 23(2R,4S,4aS)-8-((4S,5R)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 23 was prepared from Intermediate 56. The title compound wasobtained as the major eluting component from reverse phase HPLC (20-50%acetonitrile/water gradient with 0.1% TFA) purification. ¹H NMR (300MHz, DMSO-d₆) δ: 0.9 (d, 3H) 1.15 (d, 3H), 1.3 (d, 3H), 1.4 (d, 3H), 2.9(d, 1H), 3.1 (t, 1H), 3.6-3.7 (m, 2H), 3.7-3.8 (m, 1H), 3.9 (d, 1H), 4.1(d, 1H), 4.5-4.6 (m, 1H), 4.8-5.1 (m, 1H), 7.6 (s, 1H), 11.4 (s, 1H),11.8 (s, 1H). MS (ES) MH⁺: 502 for C₂₃H₂₄FN₅O₇; [α]_(D) ²⁰=−221 (c=0.1;MeOH).

Example 24(2R,4S,4aS)-8-((4R,5S)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-1-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 24 was prepared from Intermediate 57. The title compound wasobtained as the major eluting component from reverse phase HPLC (20-50%acetonitrile/water gradient with 0.1% TFA) purification. ¹H NMR (300MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.15 (d, 3H), 1.35 (d, 3H), 1.33 (d, 3H),2.8-3.0 (m, 1H), 3.1 (t, 1H), 3.5-3.7 (m, 2H), 3.7-3.9 (m, 1H), 3.9 (d,1H), 4.1 (d, 1H), 4.6 (m, 1H), 5.0 (m, 1H), 7.6 (s, 1H), 11.5 (s, 1H),11.8 (s, 1H). MS (ES) MH⁺: 502 for C₂₃H₂₄FN₅O₇; [α]_(D) ²⁰=−117 (c=0.1;MeOH).

Example 25(2R,4S,4aS)-8-((S)-4-Allyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 25 was prepared from Intermediate 61. The title compound wasobtained as the major eluting component from reverse phase HPLC (20-50%acetonitrile/water gradient with 0.1% TFA) purification. ¹H NMR (400MHz, DMSO-d₆) δ: 0.7-1.0 (m, 3H), 1.1 (d, 3H), 2.55-2.65 (m, 2H), 2.7(d, 1H), 2.8-3.0 (m, 2H), 3.1 (t, 1H), 3.5-3.7 (m, 2H), 3.7-3.9 (m, 1H),4.1 (d, 1H), 4.6-4.7 (m, 2H), 5.0-5.3 (m, 2H), 5.7-5.85 (m, 1H), 7.6 (s,1H), 11.4 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 514 for C₂₄H₂₄FN₅O₇.

Example 26(2R,4S,4aS)-11-Fluoro-8-((S)-5-(hydroxymethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 26 was prepared from Intermediate 43. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column, 70% CO₂, 30% MeOH) to isolate themajor eluting component. ¹H NMR (300 MHz, DMSO-d6) 6:0.9 (d, 3H) 1.1 (d,3H) 2.9 (d, 1H) 3.0-3.2 (m, 1H) 3.5-3.8 (m, 5H) 3.85-4.0 (m, 2H) 4.0-4.2(m, 2H) 4.75-4.9 (m, 1H) 5.2 (t, 1H) 7.8 (s, 1H) 11.4 (s, 1H) 11.75 (s,1H). MS (ES) MH⁺: 504 for C₂₂H₂₂FN₅O₈.

Examples 27 and 28((2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-q]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trioneand(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-[(4S-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 27 and Example 28 were prepared from Intermediate 65. The titlecompounds were separated by reverse phase HPLC (20-50%acetonitrile/water gradient with 0.1% TFA) purification. Twodiastereomers corresponding to the title compounds were isolated, butthe configurations for each the oxazolidinone rings were not determined.

Example 27 was the first eluting diastereomer. ¹H NMR (400 MHz, DMSO-d₆)δ: 0.9 (d, 3H), 1.15 (d, 3H), 1.2-1.5 (m, 4H), 2.9 (d, 1H), 3.0-3.3 (m,4H), 3.6-3.7 (m, 4H), 3.7-4.0 (m, 3H), 4.1 (d, 1H), 4.4-4.7 (m, 2H), 7.6(s, 1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 558 for C₂₆H₂₈FN₅O₈.

Example 28 was the second eluting diastereomer. ¹H NMR (400 MHz,DMSO-d₆) δ: 0.9 (d, 3H) 1.15 (d, 3H) 1.2-1.5 (m, 4H) 2.2-2.4 (m, 1H) 2.9(d, 1H) 3.0-3.3 (m, 3H) 3.5-3.7 (m, 2H) 3.7-4.0 (m, 4H) 4.1 (d, 1H)4.4-4.7 (m, 3H) 7.6 (s, 1H) 11.45 (s, 1H) 11.8 (s, 1H). MS (ES) MH⁺: 558for C₂₆H₂₈FN₅O₈.

Example 29(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-hydroxypropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 29 was prepared from Intermediate 69. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column) to isolate the major elutingcomponent. ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9 (d, 3H) 1.1 (d, 3H) 1.3-1.5(m, 2H) 1.7-2.0 (m, 2H) 2.9 (d, 1H) 3.0-3.2 (m, 1H) 3.3-3.45 (m, 2H)3.6-3.85 (m, 3H) 3.9-4.15 (m, 2H) 4.3-4.7 (m, 4H) 7.6 (s, 1H) 11.45 (s,1H) 11.8 (s, 1H). MS (ES) MH⁺: 532 for C₂₄H₂₆FN₅O₈.

Example 30(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

The starting material was Intermediate 70. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column) to isolate the major elutingcomponent. ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9 (d, 3H) 1.15 (d, 3H)1.5-2.05 (m, 4H) 2.9 (d, 1H) 3.05-3.2 (m, 1H) 3.6-4.2 (m, 5H) 4.3-4.7(m, 5H) 7.6 (s, 1H) 11.5 (s, 1H) 11.7 (s, 1H). MS (ES) MH⁺: 534 forC₂₄H₂₅F₂N₅O₇.

Example 31(2R,4S,4aS)-11-Fluoro-8-((S)-4-(2-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 31 was prepared from Intermediate 74. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column). ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9(d, 3H), 1.2 (d, 3H), 1.8-1.9 (m, 1H), 2.1-2.3 (m, 1H), 3.0 (d, 1H),3.1-3.2 (m, 1H), 3.5-3.6 (m, 2H), 3.6-3.7 (m, 2H), 3.8-3.9 (m, 1H), 4.0(d, 1H), 4.1 (d, 1H), 4.5 (q, 1H), 4.6-4.8 (m, 3H), 7.7 (s, 1H), 11.5,(br. s, 2H). MS (ES) MH⁺: 518.5 for C₂₃H₂₄FN₅O₈.

Example 32(2R,4S,4aS)-11-Chloro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 32 was prepared from Intermediate 77. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column, 70% CO₂, 30% EtOH) to isolate themajor eluting component. ¹H NMR (300 MHz, DMSO-d6) δ: 0.9 (d, 3H) 1.3(d, 3H) 2.9-3.1 (m, 2H) 3.6-3.7 (m, 2H) 3.8-4.0 (m, 3H) 4.25 (t, 1H)4.45-4.9 (m, 3H) 5.0-5.2 (m, 1H) 7.85 (s, 1H) 11.5 (s, 1H) 11.7 (s, 1H).MS (ES) MH⁺: 522 for C₂₂H₂₂ClFN₅O₇.

Example 33(2R,4S,4aS)-11-Choro-8-((S)-4-(3-hydroxpropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 33 was prepared from Intermediate 79. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column, 70% CO₂, 30% MeOH) to isolate themajor eluting component. ¹H NMR (300 MHz, DMSO-d6) δ: 0.9 (d, 3H) 1.15(d, 3H) 1.5-2.05 (m, 4H) 2.9 (d, 1H) 3.05-3.2 (m, 1H) 3.6-4.2 (m, 5H)4.3-4.7 (m, 5H) 7.6 (s, 1H) 11.5 (s, 1H) 11.7 (s, 1H). MS (ES) MH⁺: 534for C₂₄H₂₅F₂N₅O₇.

Example 34(2R,4S,4aS)-11-Choro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 34 was prepared from Intermediate 80. The title compound wasobtained as the major eluting component from Super Critical FluidChromatography (Chiralpak IA column, 60% CO₂, 40% MeOH) to isolate themajor eluting component. ¹H NMR (300 MHz, DMSO-d6) 6:0.9 (d, 3H) 1.2 (d,3H) 1.5-2.0 (m, 4H) 2.9-3.1 (m, 2H) 3.5-3.7 (m, 2H) 3.9-4.05 (m, 2H)4.3-4.75 (m, 6H) 7.7 (s, 1H) 11.4 (s., 1H) 11.75 (s, 1H). MS (ES) MH⁺:550 for C₂₄H₂₅ClFN₅O₇.

Example 35(2R,4S,4aS)-11-Fluoro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Intermediate 81 (445 mg, 0.99 mmol) andpyrimidine-2,4,6(1H,3H,5H)-trione (126 mg, 0.99 mmol) in a mixture ofacetic acid (8 mL) and water (2 mL) was heated at 110° C. for 2 hrs. Thesolvent was removed and the reaction mixture was purified using SuperCritical Fluid Chromatography ((S,S) Whelk-O1 column with 25% of 85:15acetonitrile methanol and 75% CO₂ mobile phase) to give(2R,4S,4aS)-11-fluoro-8-((S)-5-(methoxymethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione(368 mg, 72.1%) as a solid as the first eluting compound. ¹H NMR (300MHz, DMSO-d₆) δ: 1.0 (d, 3H), 1.3 (d, 3H), 1.4 (d, 3H), 3.1 (d, 1H),3.-4.3 (m, 7H), 4.5-4.8 (m, 2H), 7.6 (s, 1H), 11.5 (br. s., 1H), 11.7(br. s., 1H). MS (ES) MH⁺: 518 for C₂₃H₂₄FN₅O₈.

Also isolated from the synthesis of Example 35 as the second componenteluting from the HPLC purification was((2R,4R,4aR)-11-fluoro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione(27 mg)

¹H NMR (300 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.3 (d, 3H), 3.1 (d, 1H), 3.3(s, 3H), 3.5-4.3 (m, 10H), 4.8-5.1 (m, 1H), 7.8 (s, 1H), 11.4 (s, 1H),11.7 (s, 1H). MS (ES) MH⁺: 518 for C₂₃H₂₄FN₅O₈.

Example 36(2R,4S,4aS)-11-Fluoro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

A mixture of Intermediate 82 (487 mg, 1.08 mmol) andpyrimidine-2,4,6(1H,3H,5H)-trione (138 mg, 1.08 mmol) in acetic acid (8mL) and water (2 mL) was heated at 110° C. for 2 hours. The solvent wasremoved and the reaction mixture was purified using Super Critical FluidChromatography (Chiralpak IA column with 40% isopropanol and 60% CO₂mobile phase) to give the title compound (408 mg, 73.1%) as a solid asthe first eluting component. ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9 (d, 3H),1.1 (d, 3H), 2.9-3.2 (m, 2H), 3.3 (s, 3H), 3.6-4.2 (m, 9H), 4.9-5.1 (m,1H), 7.75 (s, 1H), 11.4 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 518 forC₂₃H₂₄FN₅O₈.

Example 37(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(hydroxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 87 (0.10 g, 0.22 mmol) in acetic acid (5mL), barbituric acid (0.04 g, 0.3 mmol) was added and the mixture washeated at 95° C. for 3 hours. Volatiles were removed completely undervacuum, water (2 mL) was added to the residue and filtered. The residuewas subjected to preparative HPLC using ammonium acetate method toobtain the pure title compound. Yield: 0.03 g (26%) ¹H NMR (400 MHz,DMSO-d₆) δ: 0.88 (d, 3H), 1.13 (d, 3H), 2.90 (d, 1H), 3.13 (t, 1H),3.58-3.78 (m, 5H), 3.89-3.94 (m, 2H), 4.08-4.14 (m, 2H), 4.86-4.87 (m,1H), 5.26 (t, 1H), 7.77 (s, 1H), 11.44 (s, 1H), 11.81 (s, 1H). MS (ES)MH⁺: 504.3 for C₂₂H₂₂FN₅O₈.

Example 38(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 84 (0.05 g, 0.11 mmol) in acetic acid (2mL), barbituric acid (0.02 g, 0.11 mmol) was added and the mixture washeated at 95° C. for 3 hours. Volatiles were removed completely undervacuum, water (2 mL) was added to the residue and filtered. The titlecompound obtained after purification by preparative HPLC using ammoniumacetate and acetonitrile method. Yield: 0.02 g (34%). ¹H NMR (400 MHz,DMSO-d₆) δ: 0.89 (d, 3H), 1.14 (d, 3H), 2.90 (d, 1H), 3.11 (t, 1H),3.62-3.71 (m, 2H), 3.71-3.78 (m, 1H), 3.88-3.95 (m, 2H), 4.10 (d, 1H),4.22 (t, 1H), 4.67-4.71 (m, 1H), 4.77-4.84 (m, 1H), 5.09-5.12 (m, 1H),7.76 (s, 1H), 11.46 (s, 1H), 11.83 (s, 1H). MS (ES) MH⁺: 506.5 forC₂₂H₂₁F₂N₅O₇

Example 39(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-2-oxo-4-vinyloxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

To a stirred solution of Intermediate 88 (0.15 g, 0.34 mmol) in aceticacid (5 mL), barbituric acid (0.05 g, 0.38 mmol) was added and themixture was heated at 95° C. for 3 hours. Volatiles were removed undervacuum and the resulting residue was dissolved in methanol (0.5 mL),water (3 mL) was added to it and filtered and the residue was washedwith water to obtain the title compound. Yield: 0.05 g (30%). ¹HNMR (400MHz, DMSO-d₆) δ: 0.90 (d, 3H), 1.14 (d, 3H), 2.94 (d, 1H), 3.11 (t, 1H),3.64-3.68 (m, 2H), 3.76-3.80 (m, 1H), 3.94 (d, 1H), 4.10 (d, 1H),4.28-4.31 (m, 1H), 4.76 (t, 1H), 5.11 (q, 1H), 5.30 (d, 1H), 5.36 (d,1H), 5.90 (dd, 1H), 7.57 (m, 1H), 11.48 (s, 1H), 11.84 (s, 1H). MS (ES)MH⁺: 500.3 for C₂₃H₂₂FN₅O₇.

Example 40(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 89 (0.15 g, 0.3 mmol) in acetic acid (10mL), barbituric acid (0.05 g, 0.4 mmol) was added and the mixture washeated at 95° C. for 3 hours. Volatiles were removed completely undervacuum, water (4 mL) was added to the residue and filtered. The solidthus obtained was further purified by silica gel column chromatographyusing a gradient of chloroform in methanol. We have obtained thiscompound as an undefined mixture of E & Z isomers (1:2 is the ratio).Yield: 0.06 g (34%). ¹HNMR (400 MHz, DMSO-d₆) δ: 0.89 (d, 3H), 1.14 (d,3H), 2.93 (d, 1H), 3.11 (t, 1H), 3.65-3.80 (m, 3H), 3.94 (d, 1H), 4.10(d, 1H), 4.30-4.32 & 4.47-4.51 (m, 1H), 4.76 & 4.88 (t, 1H), 5.24-5.30 &5.48-5.55 (m, 1H), 7.10-7.14 & 7.51-7.75 (m, 2H), 11.28 & 11.48 (s, 1H),11.45 (s, 1H), 11.85 (s, 1H). MS (ES) MH⁺: 517.3 for C₂₂H₂₁FN₆O₈.

Example 41(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahdro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-4-carbonitrile

To a solution Intermediate 92 (0.08 g, 0.17 mmol) in acetic acid (5 mL),barbituric acid (0.03 g, 0.2 mmol) was added and the mixture was heatedat 95° C. for 3 hours. Volatiles were removed completely under vacuum,water (2 mL) was added to the residue and filtered. The obtained solidwas further purified by preparative TLC using 9:1 mixture of chloroformand methanol. Yield: 0.03 g (34%). ¹HNMR (400 MHz, DMSO-d₆) δ: 0.89 (d,3H), 1.15 (d, 3H), 2.92 (d, 1H), 3.13 (t, 1H), 3.65-3.82 (m, 2H), 3.95(d, 1H), 4.82-4.86 (m, 2H), 5.58-5.61 (m, 1H), 7.68 (s, 1H), 11.49 (s,1H), 11.84 (s, 1H). MS (ES) MH⁺: 499.3 for C₂₂H₁₉FN₆O₇.

Example 42(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 93 (0.07 g, 0.15 mmol) in acetic acid (5mL), barbituric acid (0.03 g, 0.2 mmol) was added and the mixture washeated at 95° C. for 3 hours. The volatiles were removed completelyunder vacuum, water (2 mL) was added to the residue and filtered. Theobtained solid was further purified by preparative TLC using 9:1 mixtureof chloroform and methanol. We have obtained this compound as anundefined mixture of E & Z isomers (˜1:0.65 is the ratio). Yield: 0.03 g(30%). ¹HNMR (400 MHz, DMSO-d₆) δ: 0.89 (d, 3H), 1.13 (d, 3H), 2.93 (d,1H), 3.11 (t, 1H), 3.65-3.80 (m, 3H), 3.74 & 3.85 (s, 3H), 3.94 (d, 1H),4.10 (d, 1H), 4.30-4.32 & 4.47-4.51 (m, 1H), 4.76 & 4.88 (t, 1H),5.24-5.30 & 5.48-5.55 (m, 1H), 7.27 & 7.68 (d, 1H), 7.63 & 7.74 (s, 1H),11.45 (s, 1H), 11.82 (s, 1H). MS (ES) MH⁺: 531.2 for C₂₃H₂₃FN₆O₈.

Example 43(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 94 (0.13 g, 0.28 mmol) in acetic acid (5mL), barbituric acid (0.04 g, 0.28 mmol) was added and the mixture washeated at 95° C. for 3 hours. The volatiles were removed completelyunder vacuum, water (2 mL) was added to the residue and filtered. Thesolid thus obtained was further purified by preparative TLC using 9:1mixture of chloroform and methanol. We have obtained this compound as anundefined mixture of E & Z isomers (˜3:1 is the ratio). Yield: 0.03 g(20%). ¹HNMR (400 MHz, DMSO-d₆) δ: 0.94 (d, 3H), 1.14 (d, 3H), 2.91 (d,1H), 3.11 (t, 1H), 3.62-3.67 (m, 2H), 3.71-3.81 (m, 1H), 3.84-3.95 (m,4H), 4.10-4.16 (m, 2H), 4.29-4.39 (m, 1H), 5.37-5.42 & 5.73-5.75 (m,1H), 7.30 & 7.73 (d, 1H), 7.76 (s, 1H), 11.46 (s, 1H), 11.83 (s, 1H). MS(ES) MH⁺: 531.2 for C₂₃H₂₃FN₆O₈.

Example 44(2R,4S,4aS)-8-[(5R)-5-(Azidomethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 96 (0.12 g, 0.25 mmol) in acetic acid (3mL), barbituric acid (0.03 g, 0.25 mmol) was added and the mixture washeated at 95° C. for 3 hours. Volatiles were removed completely undervacuum, water (2 mL) was added to the residue and filtered. The residuewas subjected to preparative HPLC using formic acid/acetonitrile methodto obtain the pure title compound. Yield: 0.03 g (22%). ¹HNMR (400 MHz,DMSO-d₆) δ: 0.88 (d, 3H), 1.13 (d, 3H), 2.90 (d, 1H), 3.14 (t, 1H),3.63-3.70 (m, 2H), 3.74-3.86 (m, 4H), 3.93 (d, 1H), 4.10 (d, 1H), 4.18(t, 1H), 5.00-5.06 (m, 1H), 7.75 (s, 1H), 11.44 (s, 1H), 11.81 (s, 1H).MS (ES) MH⁺: 529.3 for C₂₂H₂₁FN₈O₇.

Example 45(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylthio)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

To a solution of Intermediate 101 (0.20 g, 0.43 mmol) in acetic acid (10mL), barbituric acid (0.066 g, 0.51 mmol) was added and the mixture washeated at 95° C. for 3 hours. The volatiles were removed completelyunder vacuum, water (2 mL) was added to the residue and filtered. Thesolid thus obtained was further purified by preparative HPLC usingammonium acetate/acetonitrile method. Yield: 0.05 g (22%). ¹H NMR (400MHz, DMSO-d₆) δ: 0.87 (d, 3H), 1.13 (d, 3H), 2.04 (s, 3H), 2.9 (d, 1H),3.01-3.07 (m, 2H), 3.10 (t, 1H), 3.62-3.68 (m, 2H), 3.75-3.79 (m, 1H),3.92 (d, 1H), 4.09 (d, 1H), 4.37 (dd, 1H), 4.67-4.72 (m, 1H), 4.78-4.83(m, 1H), 7.64 (s, 1H), 11.47 (s, 1H), 11.82 (s, 1H). MS (ES) MH⁺: 534.4for C₂₃H₂₄FN₅O₇S.

Example 46(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylsulfonyl)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 46 was synthesized following the procedure described for thepreparation of Example 45 using Intermediate 102 (0.20 g, 0.40 mmol).Yield: 0.06 (26%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.88 (d, 3H), 1.14 (d,3H), 2.92 (d, 1H), 3.09-3.14 (m, 4H), 3.63-3.69 (m, 2H), 3.77-3.82 (m,2H), 3.91-3.95 (m, 2H), 4.09 (d, 1H), 4.64 (dd, 1H), 4.78 (t, 1H),5.07-5.08 (m, 1H), 7.63 (s, 1H), 11.44 (s, 1H), 11.83 (s, 1H). MS (ES)MH⁺: 566.2 for C₂₃H₂₄FN₅O₉S; [α]_(D) ²⁰=−105.76 (c=1.00; MeOH).

Example 47 and Example 48(2R,4S,4aS)-8-((R)-4-(Azidomethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trioneand(2R,4S,4aS)-8-((S)-4-(azidomethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

To a solution of Intermediate 109 (0.25 g, 0.54 mmol) in acetic acid (10mL), barbituric acid (0.07 g, 0.54 mmol) was added and the mixture washeated at 90° C. for 16 hours. The volatiles were removed completelyunder vacuum, water (2 mL) was added to the residue and filtered. Thesolid thus obtained was further purified by silica gel columnchromatography using a gradient of methanol in chloroform. Yield: 0.25 g(86%).

Chiral HPLC analysis [chiralcel OD-H (250×4.6) mm, 5 μm; Mobile Phase‘A’ hexane; Mobile Phase ‘B’:Ethanol (50:50)] showed the presence of 1:1ratio of two isomers that were separated by Chiral HPLC [Column:chiralcel OD-H; Mobile Phase: Hexane:Ethanol (50:50)].

Example 47 was the first eluting diastereomer. ¹H NMR (400 MHz, DMSO-d₆)δ: 0.89 (d, 3H), 1.15 (d, 3H), 2.92 (d, 1H), 3.12 (t, 1H), 3.64-3.81 (m,4H), 3.94 (d, 1H), 4.09-4.15 (m, 2H), 4.37-4.43 (m, 1H), 4.67 (t, 1H),4.76-4.79 (m, 1H), 7.67 (s, 1H), 11.48 (s, 1H), 11.84 (s, 1H).R_(T)=8.21 min: Yield: 0.04 g. MS (ES) MH⁺: 529.3 for C₂₂H₂₁FN₈O₇

Example 48 was the second eluting diastereomer. ¹H NMR (400 MHz,DMSO-d₆) δ: 0.89 (d, 3H), 1.15 (d, 3H), 2.92 (d, 1H), 3.11 (t, 1H),3.63-3.79 (m, 4H), 3.94 (d, 1H), 4.09-4.16 (m, 2H), 4.39-4.41 (m, 1H),4.67 (t, 1H), 4.74-4.76 (m, 1H), 7.64 (s, 1H), 11.48 (s, 1H), 11.84 (s,1H). R_(T)=11.40 min: Yield: 0.03 g. MS (ES) MH⁺: 529.3 for C₂₂H₂₁FN₈O₇

Example 49(2R,4S,4aS)-8-[(4S)-4-(Ethoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 113 (0.20 g, 0.43 mmol) in acetic acid (4mL), barbituric acid (0.06 g, 0.43 mmol) was added and the mixture washeated at 95° C. for 2 hours. Volatiles were removed completely undervacuum, and the residue was purified by reverse phase prep. HPLC usingammonium acetate/acetonitrile method. The off white solid thus obtainedwas stirred in water (1 mL) for 10 minutes, filtered and dried. Yield:0.08 g (35%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.88 (d, 3H), 1.03 (t, 3H),1.14 (d, 3H), 2.91 (d, 1H), 3.11 (t, 1H), 3.40-3.44 (m, 2H), 3.56-3.68(m, 3H), 3.74-3.80 (m, 1H), 3.85 (dd, 1H), 3.93 (d, 1H), 4.09 (d, 1H),4.41 (dd, 1H), 4.62-4.70 (m, 2H), 7.64 (s, 1H), 11.45 (s, 1H), 11.81 (s,1H). MS (ES) MH⁺: 532.4 for C₂₄H₂₆FN₅O₈.

Example 50(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(2-methoxyethoxy)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

Example 50 was synthesized following the procedure described for thepreparation of Example 49 using Intermediate 117 (0.15 g, with 37%product). Purification was performed by reverse phase prep. HPLC usingammonium acetate/methanol method. Yield: 0.01 g. ¹H NMR (400 MHz,DMSO-d₆) δ: 0.88 (d, 3H), 1.14 (d, 3H), 2.91 (d, 1H), 3.08-3.14 (m, 1H),3.15 (s, 3H), 3.34-3.38 (m, 2H), 3.50-3.52 (m, 2H), 3.60-3.68 (m, 3H),3.74-3.80 (m, 1H), 3.88-3.94 (m, 2H), 4.09 (d, 1H), 4.40-4.43 (m, 1H),4.64-4.68 (m, 2H), 7.64 (s, 1H), 11.60 (br s, 2H). MS (ES) MH⁺: 562.4for C₂₂H₂₈FN₅O₉.

Example 51(2R,4S,4aS)-8-((R)-4-(Difluoromethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 123 (90 mg, 0.13 mmol) and 17 mg barbituricacid (17 mg, 0.13 mmol) in 2-propanol (5 mL) was heated at 90° C. for 16hours. The volatiles were removed under vacuum, and the residue wasstirred in water (5 mL) for 10 minutes and filtered. Analysis of thecollected solid residue showed the presence of mixture of twodiastereomers. The solids were suspended in methanol (5 mL) and heatedin a microwave reactor at 150° C. for 2 hours. Water (10 mL) was addedand the solids were collected by filtration and dried in vacuo. Thesolid thus obtained was further purified by preparative HPLC using anaqueous ammonium acetate/acetonitrile gradient. Yield: 70 mg (60%). ¹HNMR (400 MHz, DMSO-d₆) δ: 0.89 (d, 3H), 1.15 (d, 3H), 2.92 (d, 1H), 3.12(t, 1H), 3.65-3.72 (m, 2H), 3.78-3.82 (m, 1H), 3.95 (d, 1H), 4.11 (d,1H), 4.66 (dd, 1H), 4.73 (t, 1H), 5.04-5.10 (m, 1H), 6.59 (t, 1H), 7.64(s, 1H), 11.65 (s, 1H), 11.83 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ:−130.45 (d), −133.57 (d), −158.12 (s). MS (ES) MH⁺: 524.4 forC₂₂H₂₀F₃N₅O₇.

Example 52(2R,4S,4aS)-8-((S)-4-Cyclopropyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 128 (1.0 g, 2.48 mmol), barbituric acid (0.04g, 0.29 mmol) in 2-propanol (2 mL) was heated at 130° C. in a microwaveoven over a period of 2 hours. Volatiles were removed under vacuum andthe residue was stirred in water (5 mL) for 10 min and filtered. Thiswas suspended in methanol (2 mL) and water (5 mL) was added to that andfiltered. Yield: 1.0 g (79%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.28-0.30 (m,1H), 0.42-0.44 (m, 1H), 0.52-0.57 (m, 2H), 0.89 (d, 3H), 1.15 (d, 3H),2.94 (d, 1H), 3.12 (t, 1H), 3.62-3.69 (m, 2H), 3.73-3.82 (m, 1H), 3.95(d, 1H), 4.11 (d, 1H), 4.19-4.21 (m, 1H), 4.23-4.28 (m, 1H), 4.66 (t,2H), 7.53 (s, 1H), 11.48 (s, 1H), 11.84 (s, 1H). MS (ES) MH⁺: 514.4 forC₂₄H₂₄FN₅O₇.

Examples 53 and 54(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trioneand(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 133 (1.0 g, 2.27 mmol), barbituric acid (0.32g, 2.50 mmol) in 2-propanol (10 mL) was heated at 130° C. in a microwaveoven over a period of 2 hours. The volatiles were removed under vacuumand the residue was stirred in water (5 mL) for 10 minutes and filtered.The residue was purified in a Combi-Flash instrument using a gradient ofmethanol in chloroform. Yield: 1.0 g (80%). Chiral HPLC analysis showedthat [Column: Chiralpak IC (250×4.6) mm Mobile Phase: Hexane:Ethanol(25:75)] presence of 45%+6%+5%+42% of the isomers. The two major isomerswere separated by Chiral HPLC [Column: Chiralpak IC; Mobile Phase:Hexane:Ethanol (25:75)].

Example 53 was the first eluting diastereomer. R_(T)=8.98 min: [α]_(D)²⁵=−197.07 (c=0.123; dimethylformamide). ¹H NMR (400 MHz, DMSO-d₆) δ:0.88 (d, 3H), 1.13 (d, 3H), 2.92 (d, 1H), 3.11 (t, 1H), 3.63-3.70 (m,2H), 3.76-3.81 (m, 1H), 3.93 (d, 1H), 4.10 (d, 1H), 4.26 (dd, 1H), 4.54(t, 1H), 5.95 (dd, 1H), 7.45 (ddd, 1H), 7.62 (d, 1H), 7.78 (s, 1H), 7.91(dt, 1H), 8.65 (d, 1H), 11.40 (s, 1H), 11.80 (s, 1H). ¹⁹F NMR (376.5MHz, DMSO-d₆) δ: −158.1 (s). Yield: 0.25 g. MS (ES) MH⁺: 551.4 forC₂₆H₂₃FN₆O₇.

Example 54 was the second eluting diastereomer. R_(T)=17.50 min: [α]_(D)²⁵=−109.13 (c=0.103; dimethylformamide). ¹H NMR (400 MHz, DMSO-d₆) δ:0.88 (d, 3H), 1.14 (d, 3H), 2.92 (d, 1H), 3.12 (t, 1H), 3.62-3.69 (m,2H), 3.77-3.81 (m, 1H), 3.93 (d, 1H), 4.10 (d, 1H), 4.28 (dd, 1H), 4.52(t, 1H), 5.95 (dd, 1H), 7.45 (ddd, 1H), 7.63 (d, 1H), 7.78 (s, 1H), 7.91(dt, 1H), 8.64 (d, 1H), 11.40 (s, 1H), 11.80 (s, 1H). ¹⁹F NMR (376.5MHz, DMSO-d₆) δ: −158.1 (s). Yield: 0.22 g. MS (ES) MH⁺: 551.4 forC₂₆H₂₃FN₆O₇

Examples 55 and 56(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trioneand(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 138 (1.0 g, 2.27 mmol), barbituric acid (0.32g, 2.50 mmol) in 2-propanol (10 mL) was heated at 130° C. in a microwaveoven for 2 hours. The volatiles were removed under vacuum and theresidue was stirred in water (5 mL) for 10 min and filtered. The residuewas purified in a Combi-Flash instrument using a gradient of methanol inchloroform. Yield: 0.95 g (90%). Chiral HPLC analysis showed that[Column: Chiralpak IC (250×4.6) mm Mobile Phase: hexane:ethanol (25:75)]presence of 45%+6%+5%+42% of the isomers. The two major isomers wereseparated by Chiral HPLC [Column: Chiralpak IC; Mobile Phase:Hexane:Ethanol (25:75)].

Example 55 was the first eluting diastereomer. R_(T)=10.22 min: [α]_(D)²⁵=−339.4 (c=0.10; dimethylformamide). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.88(d, 3H), 1.12 (d, 3H), 2.91 (d, 1H), 3.09 (t, 1H), 3.60-3.67 (m, 2H),3.71-3.76 (m, 1H), 3.93 (d, 1H), 4.09 (d, 1H), 4.35-4.43 (m, 1H), 4.94(t, 1H), 5.72 (dd, 1H), 7.33-7.37 (m, 1H), 7.51 (d, 1H), 7.75 (s, 1H),7.82 (dt, 1H), 8.54 (d, 1H), 11.48 (s, 1H), 11.83 (s, 1H). ¹⁹F NMR(376.5 MHz, DMSO-d₆) δ: −158.3 (s). Yield: 0.20 g. MS (ES) MH⁺: 551.4for C₂₆H₂₃FN₆O₇.

Example 56 was the second eluting diastereomer. R_(T)=6.67 min: [α]_(D)²⁵=−109.13 (c=0.112; dimethylformamide). ¹H NMR (400 MHz, DMSO-d₆) δ:0.89 (d, 3H), 1.12 (d, 3H), 2.92 (d, 1H), 3.08 (t, 1H), 3.64-3.67 (m,2H), 3.69-3.71 (m, 1H), 3.92 (d, 1H), 4.07 (d, 1H), 4.39-4.42 (m, 1H),4.94 (t, 1H), 5.70 (dd, 1H), 7.33-7.36 (m, 1H), 7.49 (d, 1H), 7.72 (s,1H), 7.82 (dt, 1H), 8.52 (d, 1H), 11.48 (s, 1H), 11.83 (s, 1H). ¹⁹F NMR(376.5 MHz, DMSO-d₆) δ: −158.2 (s). Yield: 0.22 g. MS (ES) MH⁺: 551.4for C₂₆H₂₃FN₆O₇.

Examples 57 and 58(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trioneand(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-q][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 143 (0.52 g, 1.18 mmol), barbituric acid (0.17g, 1.3 mmol) in 2-propanol (5 mL) was heated at 130° C. in a microwaveoven for 2 hours. The volatiles were removed under vacuum and theresidue was stirred in water (5 mL) for 10 minutes and filtered. Theresidue was purified in a Combi-Flash instrument using a gradient ofmethanol in chloroform. Yield: 0.63 g (97%). Chiral HPLC analysis showedthat [Column: Chiralpak IC (250×4.6) mm Mobile Phase: Hexane:Ethanol(50:50)] presence of 41%+5%+5%+44% of the isomers. The two major isomerswere separated by Chiral HPLC [Column: Chiralpak IC; Mobile Phase:Hexane:Ethanol (25:75) with 0.1% diethylamine].: ¹H NMR of the finalcompounds suggest that the samples contain a diethylamine impurity.

Example 57 was the first eluting diastereomer. t_(R)=7.61 min: [α]_(D)²⁵=−130.1 (c=0.10; dimethylformamide). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.88(d, 3H), 1.14 (d, 3H), 2.94 (d, 1H), 3.09 (t, 1H), 3.58-3.67 (m, 2H),3.74-3.76 (m, 1H), 3.94 (d, 1H), 4.08 (d, 1H), 4.33 (dd, 1H), 4.98 (t,1H), 5.69 (dd, 1H), 7.41 (dd, 2H), 7.71 (s, 1H), 8.57 (dd, 2H). Note:Peaks corresponding to the NH protons did not appear. Yield: 0.81 g. MS(ES) MH⁺: 551.4 for C₂₆H₂₃FN₆O₇.

Example 58 was the second eluting diastereomer. t_(R)=15.38 min: [α]_(D)²⁵=−73.39 (c=0.112; dimethylformamide). ¹H NMR (400 MHz, DMSO-d₆) δ:0.89 (d, 3H), 1.13 (d, 3H), 2.92 (d, 1H), 3.08 (t, 1H), 3.62-3.66 (m,2H), 3.67-3.69 (m, 1H), 3.93 (d, 1H), 4.06 (d, 1H), 4.32 (dd, 1H), 4.99(t, 1H), 5.70 (dd, 1H), 7.39 (d, 2H), 7.70 (s, 1H), 8.55 (dd, 2H). Note:Peaks corresponding to the NH protons did not appear. Yield: 0.11 g. MS(ES) MH⁺: 551.4 for C₂₆H₂₃FN₆O₇.

Example 59(2R,4S,4aS)-11-Fluoro-8-((R)-4-((R)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 149 (0.25 g, 0.59 mmol), barbituric acid (0.08g, 0.59 mmol) in 2-propanol (9 mL) was heated in a microwave reactor at130° C. over a period of 2 h. The volatiles were removed under vacuumand the residue was stirred in water (2 mL) for 10 min and filtered.Yield: 0.26 g (81%). UPLC showed the presence of 9:1 mixture ofdiastereomers and the major isomer has been separated by chiral HPLCusing chiralpak IC [hexane:ethanol (70:30); t_(R)=8.67 min] andcharacterized. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.88 (d, 3H), 1.01 (d, 3H),1.13 (d, 3H), 2.91 (d, 1H), 3.10 (t, 1H), 3.28 (s, 3H), 3.63-3.69 (m,2H), 3.76-3.78 (m, 1H), 3.93 (d, 1H), 3.96-3.99 (m, 1H), 4.10 (d, 1H),4.46-4.49 (m, 1H), 4.59 (t, 1H), 4.76-4.79 (m, 1H), 7.62 (s, 1H), 11.48(s, 1H), 11.82 (s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −158.11 (s). MS(ES) MH⁺: 532.4 for C₂₄H₂₆FN₅O₈.

Example 60(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 156 (0.04 g, 0.1 mmol), barbituric acid (0.01g, 0.1 mmol) in 2-propanol (1 mL) was heated in a microwave reactor at130° C. over a period of 2 hours. Volatiles were removed under vacuumand the residue was stirred in water (0.5 mL) for 10 minutes andfiltered. Yield: 0.05 g (98%). UPLC showed the presence of 61%+5%+18%+3%mixture of diastereomers and the major isomer (61%) has been separatedby chiral HPLC using chiralpak IC column [hexane:ethanol (70:30);t_(R)=8.42 min] and characterized. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.89 (d,3H), 1.10 (d, 3H), 1.15 (d, 3H), 2.91 (d, 1H), 3.12 (t, 1H), 3.15 (s,3H), 3.63-3.70 (m, 2H), 3.76-3.80 (m, 1H), 3.93-3.99 (m, 2H), 4.11 (d,1H), 4.51-4.26 (m, 3H), 7.65 (s, 1H), 11.44 (s, 1H), 11.78 (s, 1H). ¹⁹FNMR (376.5 MHz, DMSO-d₆) δ: −158.17 (s). MS (ES) MH⁺: 532.5 forC₂₄H₂₆FN₅O₈

Examples 61 and 62(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trioneand(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 166 (0.12 g, 0.27 mmol), barbituric acid (0.04g, 0.27 mmol) in 2-propanol (1.5 mL) was heated at 130° C. in amicrowave oven over a period of 2 hours. The volatiles were removedunder vacuum and the residue was stirred in water (5 mL) for 10 min andfiltered. Yield: 0.13 g (87%). Chiral HPLC analysis showed that [Column:Chiralpak IA (250×4.6) mm Mobile Phase: Hexane:Ethanol (40:60)] presenceof 45%+6%+5%+42% of the isomers. The two major isomers were separated byChiral HPLC [Column: Chiralpak IA; Mobile Phase: Hexane:Ethanol(40:60)].

Example 61 was the first eluting diastereomer. t_(R)=9.43 min: [α]_(D)²⁵=−310.4 (c=0.2; MeOH). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.87 (d, 3H), 1.11(d, 3H), 2.90 (d, 1H), 3.09 (t, 1H), 3.62-3.69 (m, 2H), 3.73-3.77 (m,1H), 3.91 (d, 1H), 4.05 (d, 1H), 4.48 (dd, 1H), 4.94 (t, 1H), 5.80 (dd,1H), 7.71 (s, 1H), 8.61-8.62 (m, 2H), 8.81 (s, 1H), 11.46 (s, 1H), 11.83(s, 1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −158.25 (s). Yield: 0.04 g. MS(ES) MH⁺: 552.5 for C₂₅H₂₂FN₇O₇.

Example 62 was the second eluting diastereomer. t_(R)=18.04 min: [α]_(D)²⁵=−176.0 (c=0.2; MeOH). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.87 (d, 3H), 1.11(d, 3H), 2.90 (d, 1H), 3.08 (t, 1H), 3.60-3.75 (m, 3H), 3.91 (d, 1H),4.06 (d, 1H), 4.48 (dd, 1H), 4.95 (t, 1H), 5.81 (dd, 1H), 7.74 (s, 1H),8.62 (s, 2H), 8.82 (s, 1H), 11.47 (br s, 1H), 11.81 (br s, 1H). ¹⁹F NMR(376.5 MHz, DMSO-d₆) δ: −158.15 (s). Yield: 0.05 g. MS (ES) MH⁺: 552.5for C₂₅H₂₂FN₇O₇

Examples 63 and 64(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trioneand(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 171 (0.12 g, 0.27 mmol), barbituric acid (0.04g, 0.27 mmol) in 2-propanol (1.5 mL) was heated at 130° C. in amicrowave oven over a period of 2 hours. The volatiles were removedunder vacuum and the residue was stirred in water (5 mL) for 10 minutesand filtered. Yield: 0.13 g (87%). Chiral HPLC analysis showed that[Column: Chiralpak IC (250×4.6) mm Mobile Phase: Hexane:Ethanol (70:30)]presence of 45%+6%+5%+42% of the isomers. The two major isomers wereseparated by Chiral HPLC [Column: Chiralpak IC; Mobile Phase:Hexane:Ethanol (70:30)].

Example 63 was the first eluting diastereomer. t_(R)=13.09 min: [α]_(D)²⁵=−183.23 (c=0.31; MeOH). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.89 (d, 3H),1.13 (d, 3H), 2.92 (d, 1H), 3.10 (t, 1H), 3.63-3.77 (m, 3H), 3.94 (d,1H), 4.08 (d, 1H), 4.47 (dd, 1H), 5.01 (t, 1H), 5.71 (dd, 1H), 7.50 (t,1H), 7.82 (s, 1H), 8.84 (d, 2H), 11.51 (s, 1H), 11.83 (s, 1H). ¹⁹F NMR(376.5 MHz, DMSO-d₆) δ: −158.30 (s). MS (ES) MH⁺: 552.5 for C₂₅H₂₂FN₇O₇.

Example 64 was the second eluting diastereomer. t_(R)=30.80 min: [α]_(D)²⁵=−112.25 (c=0.38; MeOH). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.89 (d, 3H),1.13 (d, 3H), 2.94 (d, 1H), 3.10 (t, 1H), 3.64-3.79 (m, 3H), 3.94 (d,1H), 4.07 (d, 1H), 4.31 (dd, 1H), 5.01 (t, 1H), 5.68 (dd, 1H), 7.49 (t,1H), 7.75 (s, 1H), 8.82 (d, 2H), 11.46 (br s, 1H), 11.81 (br s, 1H). ¹⁹FNMR (376.5 MHz, DMSO-d₆) δ: −158.15 (s). MS (ES) MH⁺: 552.5 forC₂₅H₂₂FN₇O₇.

Example 65(2R,4S,4aS)-8-((S)-4-Ethynyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 176 (0.08 g, 0.21 mmol), barbituric acid (0.03g, 0.21 mmol) in 2-propanol (2 mL) was heated at 130° C. in a microwaveoven over a period of 2 hours. The volatiles were removed under vacuumand the residue was stirred in water (5 mL) for 10 minutes and filtered.This was suspended in methanol (0.5 mL) and water (5 mL) was added tothat and filtered. Yield: 0.09 g (92%). Reverse phase HPLC analysis inPhenomenex Gemini C18 (250×4.6) mm, 5 μm [Mobile Phase ‘A’: 10 mMAmmonium acetate in water; Mobile Phase ‘B’: Acetonitrile; t_(R)=9.72min] showed the presence of 7%+87% mixture of diastereomers and themajor isomer has been separated by reverse phase HPLC [Phenomenex GeminiC18 (Mobile Phase ‘A’: 10 mM Ammonium acetate in water; Mobile Phase‘B’: Acetonitrile)]. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.88 (d, 3H), 1.14 (d,3H), 2.92 (d, 1H), 3.11 (t, 1H), 3.62 (d, 1H), 3.64-3.68 (m, 2H),3.77-3.79 (m, 1H), 3.94 (d, 1H), 4.10 (d, 1H), 4.51 (dd, 1H), 4.80 (t,1H), 5.35-5.39 (m, 1H), 7.59 (s, 1H), 11.45 (s, 1H), 11.82 (s, 1H). MS(ES) MH⁺: 498.4 for C₂₃H₂₀FN₅O₇.

Example 66(2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((S)-4-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 66 was synthesized following the procedure described for thepreparation of Example 2 using Intermediate 177. The title compound wasobtained by chromatography on silica gel (50% Ethyl acetate in hexanes)to isolate the major eluting component, which was further purified bySuper Critical Fluid Chromatography (Chiralpak IA column) to isolate themajor eluting component. ¹H NMR (300 MHz, DMSO-d₆) δ: 0.9 (d, 3H) 1.2(d, 3H) 1.4 (d, 3H) 2.9-3.15 (m, 2H) 3.5-3.7 (m, 2H) 3.9-4.1 (m, 2H)4.1-4.25 (m, 1H) 4.4-4.8 (m, 3H) 7.7 (s, 1H) 11.4 (s, 1H) 11.8 (s, 1H).MS (ES) MH⁺: 504 for C₂₂H₂₂ClN₅O₇.

Example 67(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

A stirred solution of Intermediate 40 (0.67 g, 1.5 mmol) and barbituricacid (0.21 g, 1.6 mmol) in acetic acid (10 mL) was heated to 95° C. for4 hours. The solvents were evaporated and the residue was dissolved inmethanol (2 mL). Water (5 mL) was added to precipitate solids that werecollected and chromatographed by chiral HPLC [Chiralpak IC (250×4.6) mm;hexane:ethanol (80:20); 1.0 ml\min] to separate the title compound asthe second eluting component. ¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H),1.1 (d, 3H), 2.9 (d, 1H), 3.1 (t, 1H), 3.25 (s, 3H), 3.5 (d, 1H),3.6-3.7 (m, 2H), 3.85 (m, 1H), 3.85-3.9 (d, 1H), 3.9 (d, 1H), 4.1 (d,1H), 4.45-4.5 (m, 1H), 4.6-4.7 (m, 2H), 7.65 (s, 1H), 11.5 (s, 1H), 11.8(s, 1H). MS (ES) MH⁺: 518.4 for C₂₃H₂₄FN₅O₈; [α]_(D) ²⁰=−93.8 (c=1.14;MeOH), R_(T)=20.7 min.

Also isolated in the synthesis of Example 67 was(2S,4R,4aR)-11-fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione(first eluting component from chiral HPLC purification):

¹H NMR (400 MHz, DMSO-d₆) δ: 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.1(t, 1H), 3.2 (s, 3H), 3.5 (d, 1H), 3.6-3.7 (m, 2H), 3.85 (m, 1H),3.85-3.9 (d, 1H), 3.9 (d, 1H), 4.1 (d, 1H), 4.45-4.5 (m, 1H), 4.6-4.65(m, 2H), 7.7 (s, 1H), 11.5 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 518.4 forC₂₃H₂₄FN₅O₈; [α]_(D) ²⁰=+159.4 (c=1.04; MeOH), R_(T)=17.8 min.

Example 68(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 68 was synthesized following the procedure described for thepreparation of Example 2 using Intermediate 183. The title compound wasobtained by SFC purification using a Chiralpak OJ (250×4.6 mm) column(Carbon dioxide:Ethanol (75:25); 1.0 mL/min). ¹H NMR (400 MHz, DMSO-d₆)δ 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.15 (m, 1H) 3.5-3.8 (m, 3H),3.8-4.2 (m, 5H), 4.55 (dd, 1H), 4.8-5.1 (m, 1H), 5.0 (dd, 1H), 7.7 (s,1H), 7.9 (s, 1H) 11.4 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 558 forC₂₄H₂₃FN₈O₇.

Example 69(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 69 was synthesized following the procedure described for thepreparation of Example 2 using Intermediate 189. The title compound wasobtained by SFC purification using Chiralpak OJ (250×4.6 mm) column(Carbon dioxide:Ethanol (75:25); 1.0 ml\min). ¹H NMR (400 MHz, DMSO-d₆)δ 0.9 (d, 3H), 1.1 (d, 3H), 2.9 (d, 1H), 3.15 (m, 1H) 3.5-3.8 (m, 3H),3.8-4.2 (m, 5H), 4.55 (dd, 1H), 4.8-5.1 (m, 1H), 6.0 (dd, 1H), 7.7 (s,1H), 7.9 (s, 1H) 11.4 (s, 1H), 11.8 (s, 1H). MS (ES) MH⁺: 558 forC₂₄H₂₃FN₈O₇.

Example 70(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-q][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 198 (0.12 g, 0.30 mmol) and barbituric acid(0.04 g, 0.30 mmol) in 2-propanol (2 mL) was heated in a microwavereactor at 130° C. over a period of 2 hours. The volatiles were removedunder vacuum and the residue was stirred in water (0.5 mL) for 10 minand filtered. Yield: 0.05 g (61%) ¹H NMR (400 MHz, DMSO-d₆) δ: 0.89 (d,3H), 1.04 (d, 3H), 1.14 (d, 3H), 2.92 (d, 1H), 3.10 (t, 1H), 3.59-3.69(m, 2H), 3.77-3.78 (m, 1H), 3.94 (d, 1H), 4.10 (d, 1H), 4.32 (quin, 1H),4.45-4.49 (m, 1H), 4.53-4.55 (m, 2H), 5.29 (d, 1H), 7.73 (s, 1H), 11.83(br s, 2H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −158.38 (s). MS (ES) MH⁺:518.3 for C₂₃H₂₄FN₅O₈.

Example 71{(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidin-4-yl}acetonitrile

To a stirred solution of Intermediate 200 (0.1 g, 0.23 mmol) inisopropyl alcohol (5 mL), barbituric acid (0.03 g, 0.25 mmol) was addedand the mixture was stirred at 95° C. for 16 hours. The volatiles wereremoved completely under vacuum and water (5 mL) was added to theresidue and filtered. Yield: 0.10 g (77%). Chiral HPLC analysis [column:chiralcel OD-H, eluant: hexane:ethanol (50:50)] showed that it is amixture of four isomer in the ratio of 33:45:17:5. The isomer with theration of 33% has been separated by chiral HPLC [Column: chiralcel OD-H,eluant: hexane:ethanol (50:50)] and identified as Example 71. ¹H NMR(400 MHz, DMSO-d₆) δ: 0.89 (d, 3H), 1.15 (d, 3H), 2.92 (d, 1H),3.12-3.19 (m, 2H), 3.39-3.40 (m, 1H), 3.65-3.70 (m, 2H), 3.74-3.78 (m,1H), 3.94 (d, 1H), 4.10 (d, 1H), 4.44 (dd, 1H), 4.78 (t, 1H), 4.87-4.89(m, 1H), 7.69 (s, 1H), 11.47 (s, 1H), 11.83 (s, 1H). MS (ES) MH⁺: 513.2for C₂₃H₂₁FN₆O₇.

Example 72(2R,4S,4aS)-8-((R)-4-((R)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

To a stirred solution of Intermediate 201 (0.35 g, 0.75 mmol) in ethanol(4 mL), barbituric acid (0.19 g, 14.9 mmol) and 2 N hydrochloric acid (4mL) were added and the mixture was heated in a microwave reactor at 120°C. for 2 hours. The volatiles were removed completely under vacuum,water (3 mL) was added and solid was filtered to afford the titlecompound. Yield: 0.35 g (88%) Note: Chiral HPLC analysis [Column:Chiralpak AD-H (250×4.6) mm; Mobile Phase Hexane:Ethanol (70:30)] showedthat the reaction mixture was 89% de. The major isomer (Example 72) wasseparated by chiral HPLC [Column: Chiralpak AD-H; Mobile Phase:Hexane:Ethanol (70:30)]. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.88 (d, 3H), 1.13(d, 3H), 2.92 (d, 1H), 3.10 (t, 1H), 3.34-3.40 (m, 2H), 3.62-3.68 (m,2H), 3.75-3.79 (m, 1H), 3.92 (d, 1H), 4.09 (d, 1H), 4.18 (q, 1H),4.48-4.53 (m, 1H), 4.56-4.59 (m, 1H), 4.69-4.73 (m, 1H), 4.84 (t, 1H),5.40 (q, 1H), 7.72 (s, 1H), 11.44 (s, 1H), 11.82 (s, 1H). MS (ES) MH⁺:534.2 for C₂₃H₂₄FN₅O₉.

Example 73(2R,4S,4aS)-8-((R)-4-((S)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

Example 73 was synthesized following the procedure described for thepreparation of Example 72 using Intermediate 202 (0.40 g, 0.85 mmol).The product was obtained after subjected to reverse phase HPLCpurification by ammonium acetate method. Yield: 0.25 g (54%). Note:Chiral HPLC analysis [Column: Chiralpak AD-H (250×4.6) mm; Mobile Phase:hexane:ethanol (70:30)] showed that the reaction produced a mixture ofthe compound in 58% de. Both the major (Example 73) and minor isomerswere separated by chiral HPLC.

The major isomer (Example 73) was the second eluting diastereomer:RT=9.99 min. ¹HNMR (400 MHz, DMSO-d₆) δ: 0.88 (d, 3H), 1.13 (d, 3H),2.92 (d, 1H), 3.10 (t, 1H), 3.32-3.44 (m, 2H), 3.64-3.68 (m, 2H),3.76-3.80 (m, 1H), 3.93 (d, 1H), 4.10 (d, 1H), 4.19 (q, 1H), 4.49-4.53(m, 1H), 4.56-4.60 (m, 1H), 4.70-4.73 (m, 1H), 4.84 (t, 1H), 5.40 (q,1H), 7.72 (s, 1H), 11.43 (s, 1H), 11.81 (s, 1H). MS (ES) MH⁺: 534.2 forC₂₃H₂₄FN₅O₉.

Example 74(2R,4S,4aS)-11-fluoro-8-{(4S)-4-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione

To a solution of Intermediate 91 (0.15 g, 0.3 mmol) in acetic acid (10mL), barbituric acid (0.05 g, 0.4 mmol) was added and the mixture washeated at 95° C. for 3 hours. The volatiles were removed completelyunder vacuum, water (4 mL) was added to the residue and the solution wasfiltered. The solid thus obtained was further purified by silica gelcolumn chromatography using a gradient of chloroform in methanol. Thecompound was obtained as an undefined mixture of E & Z isomers (˜1:0.65is the ratio). Yield: 0.06 g (34%). ¹HNMR (400 MHz, DMSO-d₆) δ: 0.89 (d,3H), 1.14 (d, 3H), 2.93 (d, 1H), 3.11 (t, 1H), 3.65-3.80 (m, 3H), 3.94(d, 1H), 4.10 (d, 1H), 4.30-4.32 & 4.47-4.51 (m, 1H), 4.76 & 4.88 (t,1H), 5.24-5.30 & 5.48-5.55 (m, 1H), 7.10-7.14 & 7.51-7.75 (m, 2H), 11.28& 11.48 (s, 1H), 11.45 (s, 1H), 11.85 (s, 1H). MS (ES) MH⁺: 517.3 forC₂₂H₂₁FN₆O₈.

Examples 75 and 76(5R)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrileand(5S)-3-[(2R,4S,4aS)-11-fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrile

To a solution of Intermediate 203 (0.13 g, 0.3 mmol) in acetic acid (5mL), barbituric acid (0.04 g, 0.3 mmol) was added and the mixture washeated at 95° C. for 3 hours. The volatiles were removed completelyunder vacuum and water (2 mL) was added to the residue and the solutionwas filtered. HPLC analysis [Column Xbridge C18 (150 mm×4.6 mm) 3.5μ,mobile phase:10 mM ammonium acetate in water and methanol] showed thatthe reaction produced a 1:1 mixture of isomers, which were separated byreverse phase HPLC (Xbridge C18; mobile phase:10 mM ammonium acetate inwater and methanol). Yield: 0.03 g (34%).

Example 75 (Less polar isomer): ¹HNMR (400 MHz, DMSO-d₆) δ: 0.88 (d,3H), 1.13 (d, 3H), 2.88 (d, 1H), 3.10 (t, 1H), 3.58-3.68 (m, 2H),3.76-3.82 (m, 1H), 3.94 (d, 1H), 4.10 (d, 1H), 4.31-4.35 (m, 1H), 4.45(t, 1H), 5.88 (dd, 1H), 7.67 (s, 1H), 11.60 (br s, 2H). MS (ES) MH⁺:499.3 for C₂₂H₁₉FN₆O₇.

Example 76 (More polar isomer): ¹HNMR (400 MHz, DMSO-d₆) δ: 0.88 (d,3H), 1.13 (d, 3H), 2.90 (d, 1H), 3.11 (t, 1H), 3.64-3.70 (m, 2H),3.74-3.80 (m, 1H), 3.93 (d, 1H), 4.09 (d, 1H), 4.30-4.34 (m, 1H), 4.47(t, 1H), 5.89 (dd, 1H), 7.67 (s, 1H), 11.44 (s, 1H), 11.81 (s, 1H). MS(ES) MH⁺: 499.3 for C₂₂H₁₉FN₆O₇.

Example 77(2R,4S,4aS)-11-fluoro-8-((R)-4-((R)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 211 (0.07 g, 0.17 mmol) and barbituric acid(0.02 g, 0.17 mmol) in 2-propanol (1 mL) was heated in a microwavereactor at 130° C. over a period of 2 hours. The volatiles were removedunder vacuum and the residue was stirred in water (0.5 mL) for 10 minand filtered. Yield: 0.08 g (90%). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.89 (d,3H), 0.98 (d, 3H), 1.15 (d, 3H), 2.92 (d, 1H), 3.12 (t, 1H), 3.64-3.69(m, 2H), 3.75-3.78 (m, 1H), 3.93 (d, 1H), 4.10 (d, 1H), 4.29 (br s, 1H),4.52-4.60 (m, 3H), 5.27 (d, 1H), 7.64 (s, 1H), 11.49 (s, 1H), 11.83 (s,1H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −158.15 (s). MS (ES) MH⁺: 518.4 forC₂₃H₂₄FN₅O₈.

Example 78(2R,4S,4aS)-11-Fluoro-8-((4R,5R)-4-(fluoromethyl)-5-methyl-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 216 (0.03 g, 0.06 mmol) and barbituric acid(0.008 g, 0.06 mmol) in 2-propanol (0.5 mL) was heated at 130° C. in amicrowave reactor over a period of 2 hours. Volatiles were removed undervacuum and the residue was stirred in water (1 mL) for 10 minutes andfiltered. This was suspended in methanol (0.5 mL), water (1 mL) wasadded to that and filtered. Yield: 0.03 g (81%). ¹H NMR (400 MHz,DMSO-d₆) δ: 0.89 (d, 3H), 1.15 (d, 3H), 1.51 (d, 3H), 2.93 (d, 1H), 3.12(t, 1H), 3.65-3.70 (m, 2H), 3.77-3.78 (m, 1H), 3.95 (d, 1H), 4.11 (d,1H), 4.35-4.58 (m, 1H), 4.71 (dd, 1H), 4.86-4.89 (m, 1H), 4.99-5.01 (m,1H), 7.63 (s, 1H), 11.46 (s, 1H), 11.82 (s, 1H). MS (ES) MH⁺: 520.5 forC₂₃H₂₃F₂N₅O₇.

Examples 79 and 80(2R,4S,4aS)-11-fluoro-8-((4S,5R)-4-(methoxymethyl)-5-methyl-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trioneand(2R,4S,4aS)-11-fluoro-8-((4R,5R)-4-(methoxymethyl)-5-methyl-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-q][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione

A mixture of Intermediate 221 (0.28 g, 0.67 mmol), barbituric acid (0.09g, 0.67 mmol) in 2-propanol (5 mL) was heated at 130° C. in a microwaveoven over a period of 2 hours. The volatiles were removed under vacuumand the residue was stirred in water (5 mL) for 10 minutes and filtered.The product was suspended in methanol (0.5 mL) and water (5 mL) wasadded to that and filtered. Yield: 0.34 g (96%). Chiral HPLC [Column:Chiralpak IA (250×4.6) mm, Mobile Phase:0.1% diethylamine inHexane:Ethanol (50:50] showed the presence of 17%+51% of diastereomers.These peaks have been separated by reverse phase HPLC [Chiralpak IA;Mobile Phase: 0.1% diethylamine in Hexane:Ethanol (50:50)].

Example 79 (first eluting diastereomer): t_(R)=6.53 min; [α]_(D)²⁵=−121.46 (c=0.22; MeOH). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.88 (d, 3H),1.13 (d, 3H), 1.46 (d, 3H), 2.88 (d, 1H), 3.09 (t, 1H), 3.19 (s, 3H),3.56-3.59 (m, 2H), 3.67 (t, 1H), 3.74-3.77 (m, 1H), 3.85-3.88 (m, 1H),3.93-3.95 (m, 1H), 4.09 (d, 1H), 4.55 (s, 1H), 5.02 (t, 1H), 7.66 (s,1H), 11.40 (br s, 2H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −158.49 (s). MS(ES) MH⁺: 532.5 for C₂₄H₂₆FN₅O₈.

Example 80 (second eluting diastereomer): t_(R)=8.22 min; [α]_(D)²⁵=−129.17 (c=0.30; MeOH). ¹H NMR (400 MHz, DMSO-d₆) δ: 0.89 (d, 3H),1.14 (d, 3H), 1.45 (d, 3H), 2.90 (d, 1H), 3.12 (t, 1H), 3.22 (s, 3H),3.55-3.62 (m, 2H), 3.66 (t, 1H), 3.77-3.78 (m, 1H), 3.82-3.86 (m, 1H),3.92-3.94 (m, 1H), 4.10 (d, 1H), 4.23 (s, 1H), 4.76 (t, 1H), 7.61 (s,1H), 11.18 (br s, 2H). ¹⁹F NMR (376.5 MHz, DMSO-d₆) δ: −158.21 (s). MS(ES) MH⁺: 532.5 for C₂₄H₂₆FN₅O₈.

Biological Activity

Compounds of Formula (I) inhibit bacterial DNA gyrase and are thereforeof interest for their antibacterial effects. The compounds are activeagainst Gram-positive, Gram-negative and atypical bacteria. Theseproperties may be assessed using, for example, the assays describedbelow.

Susceptibility Testinq (MIC)— Assay 1

Minimum Inhibitory Concentrations (MICs) were determined by the brothmicrodilution method in accordance with the Clinical and LaboratoryStandards Institute (CLSI) guidelines. In brief, organism suspensionswere adjusted to a 0.5 McFarland standard to yield a final inoculumbetween 3×10⁵ and 7×10⁵ colony-forming units (CFU)/mL. Bacterial inoculawere prepared for most organisms in sterile, cation adjustedMueller-Hinton Broth (Beckton Dickinson). The streptococci were preparedas above in cation adjusted Mueller-Hinton Broth to which 2.5% lysedhorse blood (Hema Resource & Supply Inc.) was added. An inoculum volumeof 100 μL was added to wells (using a Tecan EVO robot) containing 2 μLof DMSO containing 2-fold serial dilutions of drug. All inoculatedmicrodilution trays were incubated in ambient air at 35° C. for 18-24hours. Following incubation, the lowest concentration of the drug thatprevented visible growth as read at OD600 nm and confirmed by a visualread using a test reading mirror was recorded as the MIC. Performance ofthe assay was monitored by the use of laboratory quality-control strainsand commercially available control compounds with defined MIC spectrums,in accordance with CLSI guidelines. Table 1 provides the MIC results(μM) of Examples 1-77 tested in Assay 1. Table 2 provides the MIC(μg/mL) results of Examples 78-80 tested in Assay 1.

TABLE 1 Spy^(a) Spn^(b) Spn^(c) Sau^(d) Sau^(e) Sau^(f) MIC MIC MIC MICMIC MIC Example (μM) (μM) (μM) (μM) (μM) (μM) 1 0.39 0.78 0.78 0.39 3.10.78 2 3.1 12 3.1 3.1 12 6.2 3 0.78 1.6 1.6 0.39 1.6 1.6 4 0.36 0.420.46 0.25 0.67 0.47 5 0.36 0.39 0.46 0.36 0.78 0.71 6 3.1 6.2 3.1 1.66.2 12 7 6.2 25 12 6.2 12 25 8 12 50 50 6.2 12 200 9 0.78 1.6 1.6 0.780.78 12 10 25 50 50 6.2 12 200 11 3.1 3.1 3.1 1.6 1.6 25 12 3.1 6.2 6.21.6 3.1 25 13 0.39 0.78 0.78 0.39 0.78 0.78 14 0.78 0.78 0.78 0.39 0.781.6 15 <0.20 0.28 0.39 0.28 0.78 0.39 16 0.39 0.39 0.39 0.39 1.6 1.6 170.55 0.55 0.55 0.28 0.78 0.39 18 12 3.1 6.2 3.1 6.2 12 19 <0.20 <0.200.24 0.14 0.78 0.28 20 0.28 0.28 0.28 0.28 1.1 0.39 21 0.78 1.6 1.6 0.783.1 3.1 22 0.39 0.39 0.39 <0.20 0.78 0.78 23 0.39 0.78 0.78 0.39 0.780.78 24 0.78 1.6 1.6 0.39 1.6 1.6 25 0.78 0.78 0.78 0.39 0.39 1.6 26<0.20 0.28 0.55 2.2 12 1.6 27 0.78 0.78 0.78 0.78 3.1 1.6 28 25 25 25 2550 50 29 0.39 0.39 0.78 3.1 12 3.1 30 0.39 0.39 0.39 <0.20 0.78 0.78 310.39 0.78 0.78 3.1 12 3.1 32 <0.20 0.39 0.39 <0.20 0.78 0.39 33 0.390.39 0.39 3.1 12 6.2 34 0.39 0.39 0.39 <0.20 0.78 1.6 35 0.2 0.39 0.39<0.20 1.6 0.39 36 0.78 1.6 1.6 0.78 3.1 1.6 37 0.39 0.39 0.78 3.1 25 6.238 <0.20 0.39 0.39 <0.20 1.65 0.78 39 0.39 0.78 0.78 0.39 1.6 1.6 400.28 0.39 0.78 0.78 3.1 1.6 41 0.78 0.39 0.78 0.78 1.6 1.6 42 0.39 0.390.39 <0.20 0.39 1.6 43 0.78 0.78 1.6 0.39 0.78 1.6 44 0.78 0.78 1.6 0.783.1 3.1 45 0.39 0.39 0.55 <0.20 0.39 0.78 46 0.39 0.78 1.6 1.6 6.2 1.647 0.279 0.39 0.55 <0.20 0.78 0.78 48 6.2 12 12 6.2 12 50 49 0.78 0.781.6 0.39 0.78 0.78 50 1.6 1.6 1.6 1.6 3.1 1.6 51 0.55 0.78 0.78 0.280.55 0.78 52 0.78 1.6 1.6 0.78 1.6 3.1 53 0.464 0.39 0.55 0.098 0.390.55 54 0.78 0.78 0.78 0.39 0.78 1.6 55 0.78 0.78 0.78 0.78 1.6 1.6 563.1 6.2 6.2 3.1 6.2 25 57 0.78 0.78 1.6 1.6 6.2 3.1 58 12 50 25 12 50 5059 1.6 1.6 1.6 0.78 1.6 3.1 60 1.6 1.6 1.6 0.78 1.6 1.6 61 0.78 0.780.78 0.78 3.1 1.6 62 3.1 6.2 3.1 3.1 6.2 6.2 63 0.39 0.39 0.39 0.783.1 >200 64 6.2 12 6.2 6.2 25 25 65 0.78 0.78 1.6 0.39 1.6 1.6 66 0.390.39 0.78 0.39 0.78 0.78 67 0.28 0.4 0.55 0.28 0.55 0.55 68 3.1 3.1 6.212 25 12 69 3.1 12 12 12 25 12 70 1.6 1.6 3.1 12 50 25 71 1.6 1.6 1.63.1 6.2 3.1 72 0.39 0.78 3.1 25 50 25 73 0.78 0.78 3.1 25 100 25 74 1.61.6 1.6 6.2 12 12 75 0.55 0.78 1.62 0.28 2.2 0.39 76 0.39 0.39 0.78 0.391.6 0.78 77 0.78 0.78 0.78 3.1 12 6.2 ^(a) Streptococcus pyrgenes, invivo strain. ^(b) Streptococcus pneumoniae, in vivo strain. ^(c)Streptococcus pneumoniae, in vivo strain. ^(d) Staphylococcus aureus invivo strain, MSQS. ^(e) Staphylococcus aureus, in vivo strain, MRQR.^(f) Staphylococcus aureus, serum.

TABLE 2 Spy^(a) Spn^(b) Spn^(c) Sau^(d) Sau^(e) Sau^(f) MIC MIC MIC MICMIC MIC Example (μg/ml) (μg/ml) (μg/ml) (μg/ml) (μg/ml) (μg/ml) 78 1 2 21 2 1 79 1 2 1 1 2 1 80 16 64 32 16 32 16 ^(a) Streptococcus pyrogenes,in vivo strain. ^(b) Streptococcus pneumoniae, in vivo strain. ^(c)Streptococcus pneumoniae, ATCC 49619. ^(d) Staphylococcus aureus, invivo strain, ATCC 29213. ^(e) Staphylococcus aureus, in vivo strain,MRQR. ^(f) Staphylococcus aureus, in vivo strain, MRSA.

Susceptibility Testing (MIC)— Assay 2

Minimum Inhibitory Concentrations (MICs) were determined by the brothmicrodilution method in accordance with the Clinical and LaboratoryStandards Institute (CLSI) guidelines. In brief, organism suspensionswere adjusted to a 0.5 McFarland standard to yield a final inoculumbetween 3×10⁵ and 7×10⁵ colony-forming units (CFU)/mL. Bacterial inoculawere generally prepared in sterile, cation adjusted Mueller-Hinton Broth(Becton Dickinson) which included Escherichia coli, Klebsiellapneumoniae, and Pseudomonas aeruginosa. Haemophilus influenzae bacterialinocula were prepared in sterile, cation adjusted Mueller-Hinton Broth(Becton Dickinson) containing 0.5% yeast extract (Becton Dickinson) plus30 mL of 15 μg/mL Bovine Hematin stock (Sigma), and 3 mL of 15 μg/mLβ-nicotinamide adenine dinucleotide (Sigma). Strains of Neisseria weretested for MICs using agar dilution methodology in accordance with CLSIguidelines. For broth microdilution testing, an inoculum volume of 100μL was added to wells (using a Tecan EVO robot) containing 2 μL of DMSOcontaining 2-fold serial dilutions of drug. All inoculated microdilutionpanels were incubated in ambient air at 35° C. for 18-24 hours.Following incubation, the lowest concentration of the drug thatprevented visible growth as read at OD600 nm and confirmed by a visualread using a test reading mirror was recorded as the MIC. Performance ofthe assay was monitored by the use of laboratory quality-control strainsand commercially available control compounds with defined MIC spectrums,in accordance with CLSI guidelines. Table 3 provides the MIC results(μM) of Examples 1-77 tested in Assay 2. Table 4 provides the MIC(μg/mL) results of Examples 78-80 tested in Assay 2.

TABLE 3 Hin^(a) Eco^(b) Kpn^(c) Pae^(d) Example MIC (μM) MIC (μM) MIC(mM) MIC (μM) 1 0.78 50 >200 >200 2 1.6 100 >200 >200 3 1.6 50 >200 >2004 0.47 9.9 200 >200 5 0.33 4 >200 >200 6 3.1 100 121 >200 7 12200 >200 >200 8 12 >200 >200 >200 9 0.39 50 >200 >200 1025 >200 >200 >200 11 3.1 50 >200 >200 12 3.1 100 >200 >200 13 0.78 12200 >200 14 0.78 25 200 >200 15 <0.20 12 >200 >200 16 0.78 25 200 >20017 0.39 50 >200 >200 18 3.1 >200 >200 >200 19 0.28 8.8 200 >200 20 0.3925 >200 >200 21 1.6 50 200 >200 22 0.78 12 200 >200 23 0.39 6.2 100 >20024 3.1 50 >200 >200 25 0.78 12 200 >200 26 <0.20 25 >200 >200 27 0.39100 >200 >200 28 25 >200 >200 >200 29 0.78 100 >200 >200 30 0.39 25200 >200 31 0.39 100 >200 >200 32 0.27 1.5 200 200 33 0.78 100 >200 >20034 0.39 25 200 >200 35 0.78 50 >200 >200 36 1.6 100 >200 >200 37 0.39200 >200 >200 38 0.39 25 200 >200 39 0.39 25 200 >200 40 0.3912 >200 >200 41 0.78 25 >200 >200 42 0.39 25 200 >200 43 1.650 >100 >100.000 44 0.78 50 >200 >200 45 0.39 25 200 >200 46 0.78100 >200 >200 47 0.78 25 200 >200 48 6.2 200 >200 >200 49 1.650 >200 >200 50 3.1 200 >200 >200 51 0.39 12 100 >200 52 0.78 25200 >200 53 1.1 35 >200 >200 54 3.1 100 >200 >200 55 0.39 50 >200 >20056 3.1 >200 >200 >200 57 0.39 100 >200 >200 58 6.2 >200 >200 >200 59 1.6100 >200 >200 60 1.6 100 >200 >200 61 <0.20 100 >200 >200 623.1 >200 >200 >200 63 0.39 100 >200 >200 64 3.1 >200 >200 >200 65 0.783.1 200 >200 66 0.78 6.2 100 >200 67 0.55 25 >200 >200 68 1.6200 >200 >200 69 3.1 >200 >200 >200 70 1.6 200 >200 >200 71 1.650 >200 >200 72 3.1 >200 >200 >200 73 6.2 >200 >200 >200 74 0.78100 >200 >200 75 0.78 100 >200 >200 76 0.78 50 >200 >200 77 0.78200 >200 >200 ^(a) Haemophilus influenzae, ATCC 51907, in vivo strain.^(b) Escherichia coli, K12. ^(c) Klebsiella pneumoniae, clinicalisolate, mucoid. ^(d) Pseudomonas aeruginosa, PAO1.

TABLE 4 Hin^(a) Eco^(b) Eco^(c) Kpn^(d) Kpn^(e) Pae^(f) MIC MIC MIC MICMIC MIC Example (μg/ml) (μg/ml) (μg/ml) (μg/ml) (μg/ml) (μg/ml) 78 2 1632 >64 >64 >64 79 0.5 32 64 >64 >64 >64 80 1 >64 >64 >64 >64 >64 ^(a)Haemophilus influenzae, ATCC 49247. ^(b) Escherichia coli, in vivostrain, ATCC 25922. ^(c) Escherichia coli, ATCC 35218. ^(d) Klebsiellapneumoniae, clinical isolate, mucoid. ^(e) Klebsiella pneumoniae, ATCC700603. ^(f) Pseudomonoas aeruginosa, PAO1.

DNA Gyrase Supercoilinq Activity Fluorescence Polarisation Assay

In a black, 384-well polystyrene assay plate, 30 microliters/well of 5nM Escherichia coli DNA gyrase A/B tetramer and 130 micrograms/mL oftopologically relaxed plasmid containing the triplex-forming sequenceTTCTTCTTCTTCTTCTTCTTCTTCTTC (SEQ ID NO:1) in an assay buffer consistingof 35 mM Tris-HCl (pH 7.5), 24 mM KCl, 4 mM MgCl2, 2 mM dithiothreitol,1.8 mM spermidine, 5% (v/v) glycerol, 200 nM bovine serum albumin, 0.8%dimethylsulfoxide, and 0.3 mM ATP were incubated at ambient temperaturefor (typically 30 minutes) in the absence or presence of 5-10 differentconcentrations of test compound. The supercoiling reactions werequenched by the addition of 10 microliters/well of 40 nMoligodeoxynucleotide probe in 3× triplex-forming buffer consisting of150 mM NaCl, and 150 mM sodium acetate at pH 3.5. Theoligodeoxynucleotide probe was 5′-BODIPY-FL-labeled TTCTTCTTC (SEQ IDNO:2). After 60 minutes, the fluorescence anisotropy of the BODIPY-FLwas measured in a Tecan Ultra plate reader, using 485 nm excitation and535 nm emission filters equipped with polarizers. The IC₅₀ wasdetermined by nonlinear regression using two control reactions. Thefirst contained no test compound but 0.8% DMSO (100% activity) while thesecond control reaction contained 5 μM Ciprofloxacin and 0.8% DMSO (0%activity).

When tested in an in vitro assay based on the DNA gyrase supercoilingactivity fluorescence polarization assay described above, the E. coliDNA gyrase supercoiling IC₅₀ assay inhibitory activities of Examples1-77 were determined, as shown in Table 5.

TABLE 5 Eco Gyr FP Example Mean IC50 (μM) 1 1.3 2 2.7 3 1.44 4 0.39 50.169 6 3.3 7 9.7 8 7.3 9 0.71 10 6.7 11 1.2 12 3.2 13 0.51 14 0.57 150.13 16 0.19 17 0.14 18 0.81 19 0.16 20 0.42 21 0.54 22 0.21 23 0.5224 >2.1 25 0.26 26 0.17 27 0.53 28 >2.1 29 0.27 30 0.5 31 0.42 32 0.6333 0.26 34 0.23 35 0.31 36 0.59 37 0.12 38 0.067 39 0.097 40 0.38 410.46 42 0.29 43 0.44 44 0.53 45 0.26 46 0.17 47 0.15 48 >2.1 49 0.38 500.2 51 0.43 52 0.9 53 0.38 54 0.94 55 0.15 56 1.9 57 0.76 58 1.5 59 0.8660 0.95 61 0.34 62 1.4 63 0.38 64 >2.1 65 0.12 66 0.17 67 0.33 68 0.2269 0.6 70 0.61 71 0.16 72 0.29 73 0.34 74 0.47 75 0.71 76 0.55 77 0.5378 0.44 79 >2.1 80 0.17In Vivo Efficacy of Example 5 Against Staphylococcus aureus in a MouseThigh Model

The objective of the study was to determine the efficacy andpharmacokinetic/pharmacodynamic (PK/PD) relationship for Example 5against Staphylococcus aureus (S. aureus) in mouse thigh infectionmodels.

The S. aureus strains used included a methicillin-resistant isolateobtained from the American Type Culture Collection (ATCC33591) (MRSA).In addition, three S. aureus clinical isolates were utilized; (1) amethicillin sensitive isolate (MSSA); (2) a recent methicillin-resistantclinical isolate of the USA300 genotype (USA300) and (3) a recentmethicillin-resistant clinical isolate of the USA100 genotype (USA1000).

The MIC against each isolate was determined using the brothmicrodilution method following CLSI guidelines (Rayner et al. Clinicalpharmacodynamics of Linezolid in seriously ill patients treated in acompassionate use program. Clin Pharmacokinet 2003. 42:1411-23). Tenindividual determinations were performed for each strain and the ModalMIC was used for all PK/PD calculations.

All procedures were carried out according to Institutional Animal Careand Use Committee (IACUC) approved protocol 11-03-i. Mice were renderedneutropenic with cyclophosphamide at 150 mg/kg ip on day −4 and 100mg/kg ip on day −1 (Andes et al. In vivo pharmacodynamics of a newOxazolidinone (Linezolid) AAC 2002, 46(11): 3484-9).

Two hours prior to infection, mice received an administration of 50mg/kg aminobenzotriazole (ABT) orally to inhibit cytochrome P450(CYP450) activity; mice received a second 50 mg/kg administration 12 hlater. Each S. aureus isolate was prepared in a similar fashion. A freshovernight plate was used to inoculate a 25 mL culture of Tryptic Soybroth (TSB). The culture was incubated overnight at 37° C. with 200 rpmshaking. The overnight culture was diluted 1:10 in TSB, the OD600determined, and entered into a dilution calculator specific for thatisolate. The calculated volume of the overnight culture was pipettedinto the appropriate volume of saline to obtain the target inoculumlevel of 5×105 CFU/thigh and a viable count determined in duplicate.

Mice were then assigned to control or treatment groups. At 2 hours afterinfection, one group of 10 mice was euthanized to determine the viablecount in the infected thighs at start of treatment. The remaining groupsof mice were administered (1) Example 5, (2) control compounds(levofloxacin or linezolid) or (3) vehicle. Efficacy was determined 24hours after start of treatment. Mice were euthanized by carbon dioxideasphyxiation and cervical dislocation and the infected thigh removed anddissected. The thighs were weighed and transferred to tubes containing 1mL of saline for homogenization. Thigh tissue was homogenized (Omni THhomogenizer, Omni International, Warrenton, Va.) and 100 μL ofhomogenate serially diluted in saline and plated onto tryptic soy agarplates for viable count determination. Plates were incubated at 37° C.overnight.

Initially, single dose time course studies were run for each isolate todetermine the optimal dosing regimen. For the S. aureus MRSA isolateonce daily (uid) dosing was determined to be the optimal regimen, forall other isolates a twice daily (bid, q12) regimen was determined to beoptimal. Following the time course study two individual dose responsestudies were run for each isolate and the results were combined toobtain the AUC/MIC ratios associated with efficacy. The mice were dosed2.5 to 160 mg/kg/day given qd or bid q12, the volume of administrationwas 10 mL/kg by bolus intraperidoneal dose and the duration of treatmentwas 24 hours.

Groups of satellite mice infected with S. aureus were used fordetermining plasma concentrations. Dosing started 2 hours afterinfection and whole blood samples were taken at time points 0.5, 1, 2,4, 6, 8, 12 and 24 h by submandibular bleed or by cardiac puncturefollowing carbon dioxide asphyxiation and cervical dislocation. Wholeblood was sampled into microcontainer tubes containing ethylenediaminetetraacetic acid (EDTA) (Beckton Dickenson). Three mice per time pointwere used. Plasma was separated by centrifugation for five minutes at13200 rpm and stored at −20° C. until bioanalysis.

Biological samples containing Example 5 were extracted using proteinprecipitation. To one volume of sample, 5 volumes of acetonitrilecontaining the internal standard (Glyburide) were added. The mixture wasthen mixed and the plate was centrifuged at 3200 rpm for 5 min. A 200 μLvolume of the supernatant was dried down and, reconstituted in mobilephase and the mixture was injected onto liquid chromatography-massspectrometry (LC-MS). A Sciex API 4000, controlled by Analyst v1.4.2,was used for the acquisition of the data and the quantification ofExample 5. LC-MS instrument parameters are provided in Tables 6 and 7,below.

TABLE 6 Liquid Chromatography conditions to detect Example 5 in plasmaParameter Condition Column ACE C8, 20 x 2.1 mm Column Temperature RoomTemperature Flow rate 0.60 mL/min Gradient Time (min) % B 0.50 10 1.5095 2.00 95 2.01 10 2.30 Stop Mobile Phase A 10 mM Ammonium Formate +0.1% Ammonium Hydroxide Mobile Phase B ACN with 0.1% Ammonium HydroxideSyringe Wash 1 1:1:1:1 MeOH:CAN:IPA:H₂O + 0.2% [NH₄OH] Syringe Wash 210:90 MeOH:H₂O + 0.2% Formic Acid

TABLE 7 MS/MS parameters for Example 5 and Glyburide detection ParameterCondition Mass Sciex API 4000 Spectrometer Source 550° C. temperatureInjection 10 μL volume Ion mode ESI− MRM Compound ID Q1 Q3 DP CE CXPtransitions Example 5 486.13 42.09 −85 −65 −5 Glyburide 492.00 170.00−55 −4- −10

Pharmacokinetic Data Analysis:

The plasma profile for each dose group was obtained by calculating theaverage plasma concentration of compound in each of the three animalsper time point. The area under the plasma concentration time curve fromzero to infinity (AUC); maximum plasma drug concentration (C_(max));time to reach maximum concentration (t_(max)); and plasma half-life(t_(1/2)) for each dose group was determined by non-compartmentalanalysis (WinNonLin 5.2, Pharsight). The non-compartmental Model 200 wasused in the analysis.

The AUC for the bid dose regimens were determined by multiplying the AUCvalue obtained after a single dose by two, assuming no accumulationfollowing a second dose. Pharmacodynamic Data Analysis: The number ofbacterial colonies grown from the thigh of each animal was adjusted toaccount for sample dilution and tissue weight to determine the CFU pergram of tissue (CFU/g). The variability in each dose group wasdetermined by calculating the standard error across the animals withinthe each group.

Pharmacokinetic/Pharmacodynamic Analysis:

The mean log CFU/g obtained for the pre-treatment group was subtractedfrom the log CFU/g obtained for each individual animal in the treatmentgroups. The delta in log CFU/g was determined for each animal in theefficacy group and used in the PK/PD analysis. Statistical outliers weredetermined using the interquartile method and eliminated from theanalysis.

The pharmacokinetic parameters of AUC for each dose group were relatedto the MIC of Example 5 against the each S. aureus isolate. The ratio ofthe AUC to the MIC was determined for each dose group and plottedagainst the CFU/g of each animal.

A murine unbound fraction of 22.1% was used to calculate free plasmaconcentrations. This value came from the mean of the mouse proteinunbound fraction of Example 5 in the range of 1 μM to 50 μM.

The correlation between efficacy and the PK/PD indices total AUC wasdetermined by non linear regression (WinNonlin 5.2, Pharsight). The datawas modeled using a sigmoidal E_(max) model shown below, where E_(max)is the maximum growth observed in the absence of drug; E₀ is the maximumkill, EC₅₀ is the concentration that gives 50% of response, and N is theHill factor.

$E = {E_{\max} - {\left( {E_{\max} - E_{0}} \right) \cdot \frac{C^{N}}{C^{N} + {EC}_{50}^{N}}}}$

The PK/PD analysis was performed on the combined dose groups as well asfor the individual dose regimens. The goodness of fit was determined byevaluating the variability in the model-calculated parameters, theAikaike criteria, and the analysis of the weighted residuals.

The PK/PD parameters determined by modeling were used to determineexposures required to reach a static response and as well as 1 logreduction on colony counts compared to the counts at the start oftherapy.

The MIC values of the four S. aureus isolates determined against Example5 are presented in Table 8.

TABLE 8 Modal MIC values against S. aureus isolates Strain Example 5 MIC(μg/mL) MSSA 0.0625 MRSA 0.125 USA100 0.125 USA300 0.25

The plasma exposures associated with intraperitoneal administration ofExample 5 in the presence of ABT were determined in neutropenic micethigh infected with S. aureus MSSA, MRSA and USA300. The combined datawas analyzed to build a consensus dose/exposure relationship. The bestrelationship was associated with a power relationship,Y=(1,022.7)*(X^(1.2019)), where Y is the AUC infinity in ηg h/mL and Xis the measured dose in mg/kg.

FIG. 1 illustrates Example 5 dose response against S. aureus USA100 inthe thigh of neutropenic mice, pre-treated with ABT. Each pointrepresents the mean of 5 animals The error bars represent the standarderror. At the start of therapy the bacterial burden was 5.93±0.09 CFU/g.The bacteria grew 3.3 log CFU/g in the vehicle group. Linezolid wasadministered intrapertoneally in separate experiments for comparison.

Each S. aureus isolate grew at least two logarithms in the vehiclecontrol group from the start of treatment; with MSSA, MRSA, USA100 andUSA300 growing 1.96±0.08, 3.2±0.12, 2.66±0.16 and 3.1±0.21 CFU/g,respectively. S. aureus MRSA was administered once daily (uid) as noneof the doses tested re-grew to levels equivalent to the vehicle controlgroup. The other three isolates were tested with an administrationregime of two equal doses administered twelve hours apart (bid, q12).

The PK/PD parameters from the simple dose response studies werecalculated. It was assumed that the AUC/MIC parameter was the parameterthat best correlated with activity as this driver has been shown tocorrelate best with efficacy both in vitro. For all dose responsestudies the dosing solutions were analyzed to assess the measured doseand the consensus exposure relationship was used to estimate plasmaexposure.

The PK/PD parameters for S. aureus MSSA in the neutropenic mouse modelwere generated from two dose response studies. The AUC values for stasisand a 1-log reduction were determined to be 28 and 69 μg.h/mL,respectively.

The PK/PD parameters for S. aureus MRSA in the neutropenic mouse modelwere generated from the results of two dose response studies. The AUCvalues for stasis and a 1-log reduction were determined to be 24 and 55μg.h/mL, respectively.

The PK/PD parameters for S. aureus USA300 in the neutropenic mouse modelwere generated from the results of two dose response studies. The AUCvalues for stasis and a 1-log reduction were determined to be 91 and 150μg.h/mL, respectively.

The PK/PD parameters for S. aureus USA100 in the neutropenic mouse modelwere generated from the results of two dose response studies. The AUCvalues for stasis and a 1-log reduction were determined to be 25 and 47μg.h/mL, respectively.

Calculated Free AUC/MIC Ratios for Efficacy

The free plasma AUC/MIC magnitudes calculated for the S. aureus animalmodels are presented in Table 9.

TABLE 9 Free plasma AUC/MIC magnitudes for Example 5 versus S. aureusisolates In vivo model N^(a) End point AUC/MIC (free) S. aureus MSSA 2EC₅₀ ± SEM (% CV)^(b)  71 ± 28 (44%) neutropenic Stasis ± SEM (% CV)^(c) 98 ± 17 (17%) dose response 1-log reduction ± SEM (% CV)^(d) 245 ± 81(33%) S. aureus MRSA 2 EC₅₀ ± SEM (% CV)  53 ± 25 (47%) neutropenicStasis ± SEM (% CV) 43 ± 5 (11%) dose response 1-log reduction ± SEM (%CV)  96 ± 35 (36%) S. aureus USA300 2 EC50 ± SEM (% CV)  73 ± 38 (52%)neutropenic Stasis ± SEM (% CV) 80 ± 5 (12%) dose response 1-logreduction ± SEM (% CV) 132 ± 16 (12%) S. aureus USA100 2 EC50 ± SEM (%CV)  34 ± 14 (40%) neutropenic Stasis ± SEM (% CV) 43 ± 5 (12%) doseresponse 1-log reduction ± SEM (% CV)  83 ± 23 (28%) ^(a)Number ofstudies. ^(b)Effect concentration median ± Standard error of the mean (%coefficient of variance). ^(c)Stasis ± Standard error of the mean (%coefficient of variance). ^(d)1-log reduction ± Standard error of themean (% coefficient of variance).

Summary

Example 5 showed nonlinear pharmacokinetics over the dosing range.Absorption was good, with maximum concentration attained at 0.5 hpost-administration. A dose/exposure relationship was built based uponthe plasma PK exposures from a number of efficacy studies and themeasured concentration of the dosing solutions. This consensus exposurewas utilized, in conjunction with the modal MIC values for theindividual isolates and the mouse free plasma levels to determine thefree AUC/MIC magnitude associated with a bacteriostatic effect and for a1-log reduction in the model.

Dose response studies were run in the neutropenic thigh model todetermine the relative free AUC/MIC magnitudes required for efficacy.The free AUC/MIC ratio required for a bacteriostatic effect and for a1-log reduction, relative to the initial bacterial burden for rangedfrom 43 to 98 and 83 to 245, respectively.

In Vivo Efficacy of Example 5 Against Streptococcus pyogenes in a MouseThigh Model

The objective of the study was to determine the efficacy andpharmacokinetic/pharmacodynamic (PK/PD) relationship for Example 5against Streptococcus pyogenes (S. pyogenes) in mouse neutropenic thighinfection model. S. pyogenes ATCC12384 obtained from the American TypeCulture Collection was used in this study

The MIC against S. pyogenes ATCC12384 was determined using the brothmicrodilution method following CLSI guidelines. Three individualdeterminations were performed for each strain and the Modal MIC was usedfor all PK/PD calculations. All animal experiments were performed underUK Home Office Licensure with local ethical committee clearance. Allexperiments were performed by technicians who have completed parts 1, 2and 3 of the Home Office Personal License course and hold currentpersonal licenses.

All mice were rendered temporarily neutropenic by immunosuppression withcyclophosphamide (Baxter, Norfolk, UK) at 150 mg/kg 4 days beforeinfection and 100 mg/kg one day before infection by intraperitonealinjection (Andes et al, infra). Twenty four hours after the second roundof immunosuppression, mice were infected with S. pyogenes, ATCC12384 byintramuscular injection into both lateral thigh muscles under temporaryinhaled anaesthesia (3% Isoflurane) using ˜5×10⁵ CFU/mouse thigh.Buprenorphine 0.06 mg/kg was administered subcutaneously (SC) to allmice in the study, in this study pain in the thigh typically causeslameness and loss of use of the effected limb. Buprenorphine wasre-administered at 12 hourly intervals starting at the time of infectionto ensure on-going pain relief.

In the efficacy studies, 6 mice were used in the 2 h post-infectionpre-treatment group; 8 mice were used in the vehicle control andtherapeutic treatment groups. Fifteen minutes prior to and twelve hoursafter infection animals to be treated with test agents and vehicle wereadministered with 50 mg/kg 1-aminobenzotriazole by oral gavage.Antibacterial treatments were administered 2 h and 14 h post infection,delivered at 10 mL/kg intraperitoneally. The comparator group wastreated with 100 mg/kg linezolid at 2 h and 14 h post infection by SCdelivery. The control group was treated with vehicle (0.2M meglumine/30%HPβCD) only.

For efficacy studies 24 h post infection (or earlier if the mice reachedpre-defined endpoints), the clinical condition of all animals wasassessed prior to them being humanely euthanized using pentabarbitoneoverdose. Both thighs were removed and weighed individually. Individualthigh tissue samples were homogenized using a bead-beater in ice coldsterile phosphate buffered saline. Thigh homogenates were thenquantitatively cultured onto blood agar and incubated at 37° C. for 24 hbefore being counted.

Groups of satellite mice infected with S. pyogenes, as described above,were used for determining plasma concentrations. Dosing started 2 hoursafter infection and whole blood samples were taken at 0.5, 1, 2, 4, 6,8, 12 and 24 h. Mice from the satellite PK study were euthanized byinhaled 5% isofluorane at specified time points post-treatment, micewere bled immediately by cardiac puncture. Heparinised blood sampleswere separated by centrifugation for five minutes at 13200 rpm. Plasmasamples were stored at minus 80° C. before transfer to the client foranalysis.

For the PK arm of the study, 3 mice per time point per unit dose wereused. Due to unintended changes in the final work order, the 80 and 160mg/kg dosing groups initially were administered Example 5 without priortreatment with aminobenzotriazole. Once this was realised, the remainingmice were re-distributed across the dosing groups and group size wasreduced to two mice per time point.

Biological samples containing Example 5 were extracted using proteinprecipitation. To one volume of sample, 5 volumes of acetonitrilecontaining the internal standard (Glyburide) were added. The mixture wasthen mixed and the plate was centrifuged at 3200 rpm for 5 min. A 200 μLvolume of the supernatant was dried down and, reconstituted in mobilephase and the mixture was injected onto liquid chromatography-massspectrometry (LC-MS). A Sciex API 4000, controlled by Analyst v1.4.2,was used for the acquisition of the data and the quantification ofExample 5. LC-MS instrument parameters are provided in Tables 6 and 7.

The plasma profile for each dose group was obtained by calculating theaverage plasma concentration of compound in each of the two to threeanimals per time point. The area under the plasma concentration timecurve from zero to infinity (AUC); maximum plasma drug concentration(C_(max)); time to reach maximum concentration (t_(max)); and plasmahalf-life (t_(1/2)) for each dose group was determined bynon-compartmental analysis (WinNonLin 5.2, Pharsight). Thenon-compartmental Model 200 was used in the analysis. The AUC for thebid dose regimens were determined by multiplying the AUC value obtainedafter a single dose by two, assuming no accumulation following a seconddose. The number of bacterial colonies grown from the thigh of eachanimal was adjusted to account for sample dilution to determine the CFUper thigh (CFU/thigh). The variability in each dose group was determinedby calculating the standard error across the animals within the eachgroup.

The mean log CFU/g obtained for the pre-treatment group was subtractedfrom the log CFU/g obtained for each individual animal in the treatmentgroups. The delta in log CFU/g was determined for each animal in theefficacy group and used in the PK/PD analysis. Statistical outliers weredetermined using the interquartile method and eliminated from theanalysis.

The pharmacokinetic parameters of AUC for each dose group were relatedto the MIC of Example 5 against S. pyogenes ATCC12384. The ratio of theAUC to the MIC was determined for each dose group and plotted againstthe CFU/thigh of each animal. A murine unbound fraction of 22.1% wasused to calculate free plasma concentrations. This value came from themean of the mouse protein unbound fraction of Example 5 in the range of1 μM to 50 μM.

The correlation between efficacy and the PK/PD indices total AUC wasdetermined by non-linear regression (WinNonlin 5.2, Pharsight). The datawas modelled using a sigmoidal E_(max) model shown below, where E_(max)is the maximum growth observed in the absence of drug; E₀ is the maximumkill, EC₅₀ is the concentration that gives 50% of response, and N is theHill factor.

$E = {E_{\max} - {\left( {E_{\max} - E_{0}} \right) \cdot \frac{C^{N}}{C^{N} + {EC}_{50}^{N}}}}$

The PK/PD analysis was performed on the combined dose groups as well asfor the individual dose regimens. The goodness of fit was determined byevaluating the variability in the model-calculated parameters, theAikaike criteria, and the analysis of the weighted residuals.

The PK/PD parameters determined by modelling were used to determineexposures required to reach a static response and as well as a 1-log anda 2-log reduction on colony counts compared to the counts at the startof therapy.

The MIC value for S. pyogenes ATCC12384 determined against Example 5 was0.125 μg/mL.

The plasma exposures associated with intraperitoneal administration ofExample 5 in the presence of ABT were determined in neutropenic micethigh infected with S. pyogenes ATCC12384. The calculatedpharmacokinetic parameters calculated for each satellite PK arepresented in Table 10. This data was compared to a consensusdose/exposure relationship built for plasma exposures in the S. aureusneutropenic thigh model. The consensus relationship was defined asY=(1,022.7)*(X^(1.2019)), where Y is the AUC infinity in ηg h/mL and Xis the measured dose in mg/kg.

TABLE 10 Plasma pharmacokinetics of Example 5 administered in thepresence of ABT in S. pyogenes infected mice. Dose (mg/kg) AUCinfNominal Measured (ng hr/mL) 10 4.1 32629 40 25.4 108851 60 44.2 15329580 66.2 251172 160 142.0 613542

FIG. 2 illustrates Example 5 dose response against S. pyogenes ATCC12384in the thigh of neutropenic mice, pre-treated with ABT. Each pointrepresents the mean of 16 thighs. At the start of therapy the bacterialburden was 6.38±0.03 CFU/g. The bacteria grew 2.6-log CFU/g in thevehicle group. Amoxicillin was administered intrapertoneally in aseparate experiment for comparison.

The PK/PD parameters from the dose response study were calculated. Itwas assumed that the AUC/MIC parameter is the parameter that bestcorrelates with activity as this driver has been shown to correlate bestwith efficacy both with previous compounds in the series and was highlyassociated with efficacy in vitro. The dosing solutions were analyzed toassess the measured dose and the consensus exposure relationship wasused to estimate plasma exposure. Calculated AUC values are presented inμg h/mL.

The PK/PD parameters for S. pyogenes ATCC12384 in the neutropenic mousemodel were generated from a single dose response study. The AUC valuesfor stasis, 1-log and 2-log reduction were determined to be 60, 76 and95 μg.h/mL, respectively.

The free plasma AUC/MIC magnitudes calculated for the S. pyogenesATCC12384 are presented in Table 11.

TABLE 11 Free plasma AUC/MIC magnitudes for Example 5 versus S. pyogenesATCC12384 In vivo model N^(a) End point AUC/MIC (free) S. pyogenes 1EC₅₀ ± SEM (% CV)^(b) 151 ± 7 (5%) neutropenic Stasis ± SEM (% CV) 106 ±5 (5%) dose response 1-log reduction ± SEM (% CV) 135 ± 5 (4%) 2-logreduction ± SEM (% CV) 168 ± 6 (4%) ^(a)Number of studies. ^(b)Effectconcentration median ± Standard error of the mean (% coefficient ofvariance).

Summary

Example 5 pharmacokinetics over the dosing range demonstrated exposuresconsistent with the exposures demonstrated in the S. aureus neutropenicthigh model. The consensus exposure was utilized, in conjunction withthe S. pyogenes ATC12384 MIC value and the mouse free plasma levels todetermine the free AUC/MIC magnitude associated with a bacteriostaticeffect and for a 1- and 2-log reduction in the model.

Example 5 showed dose-dependent efficacy in vivo against S. pyogenesATC12384 in neutropenic mice. The free AUC/MIC ratio required for abacteriostatic effect and for 1- and 2-log reductions, relative to theinitial bacterial burden were 106, 135 and 168, respectively.

In Vitro Antibacterial Activity of Example 5

The goal of this study was to determine the in vitro antibacterialactivity of Example 5 against a collection of Gram-positive,Gram-negative, fastidious, and anaerobic bacterial isolates. Testingperformed included minimum inhibitory concentration (MIC), minimumbactericidal concentration (MBCs), and MICs in the presence of serum(mouse and human). The bacterial isolates utilized in these studiesconsisted primarily of recently obtained geographically diverse clinicalisolates, but also included CLSI quality control reference strains,internal screening panel cultures, and isolates with defined resistancemechanisms.

MIC values were determined using either CLSI broth microdilution or agardilution (N. gonorrhoeae) methodology. For broth microdilutionsusceptibility testing, stock compound mother plates were prepared andused to spot 2 μL aliquots of serial 2-fold drug dilutions into columns1-11 of 96-well daughter plates. Column 12 did not contain drug andserved as the growth control. An inoculum volume of 100 μL (5×10E⁵CFU/mL) was added directly to each well of the 96-well plate usingeither a Tecan Freedom EVO or a Perkin-Elmer MiniTrak™ MultiPositionliquid handling robot. The MIC Range, MIC₅₀ and MIC₉₀ were determinedfor organism groups containing ≧10 isolates. The MIC₅₀ and MIC₉₀ weredefined as the concentration of compound that inhibited the growth of,respectively, 50% and 90% of the combined sets of clinical isolatestested. At least one CLSI quality control reference organism and controlcompound was used to validate the susceptibility testing to ensure therewas no variation between test dates or the control compounds. The MICand MBC values obtained for each organism/drug combination weredetermined following Clinical and Laboratory Standards InstituteGuidelines (Methods for dilution antimicrobial susceptibility tests forbacteria that grow aerobically; approved standard. Ninth edition. Wayne,Pa. Volume 32. Number 2; Methods for antimicrobial susceptibilitytesting of anaerobic bacteria; approved standard. Seventh edition.Wayne, Pa. Volume 27 Number 2; and Methods for determining bactericidalactivity of antimicrobial agents; approved guideline. Wayne, Pa. Volume19 Number 18). Susceptibility breakpoint interpretations for referencecompounds along with QC ranges for reference bacterial strains aredescribed in CLSI documents Performance standards for antimicrobialsusceptibility testing; twenty-first informational supplement. Wayne,Pa. Volume 31. Number 1, and Performance standards for antimicrobialsusceptibility testing; twenty-second informational supplement. Wayne,Pa. Volume 32. Number 3. Broth microdilution MIC testing was performedfor all species tested with the exceptions of anaerobes and Neisseriagonorrhoeae which utilized agar dilution. Broth microdilution MICs forLegionella pneumophila were performed in Legionella broth. Strains of L.pneumophila were initially grown on buffered charcoal yeast extract(BCYE) agar plates for 48 hours prior to transfer.

MIC values for individual isolates were read visually, MICdeterminations (MIC range, MIC₅₀, MIC₉₀) and cumulative percentinhibition plots were generated using CUMPER (short for CumulativePercentage); an in-house statistical software program.

The antibacterial spectrum of Example 5 against individualGram-positive, Gram-negative, and anaerobic bacterial isolates ispresented in Tables 12 and 13. Overall, Example 5 was active against thestaphylococci, streptococci, Haemophilus influenzae, Moraxellacatarrhalis, Clostridium spp., Finegoldia magna, and Prevotellamelaminogenica isolates tested. The antibacterial activity of Example 5and comparators was also evaluated against Staphylococcus aureus,Streptococcus pneumoniae, and S. pyogenes strains with characterizedgyrase and topoisomerase mutations. No cross resistance was found forExample 5 against bacterial clinical isolates possessing frequentlyencountered mutations in either gyrA, gyrB, ParC, or ParE, which areknown to cause resistance to quinolones, novobiocin and Coumermycin A1.

Example 5 and comparators were evaluated in MIC₉₀ studies against acollection of 676 recently obtained Gram-positive and fastidiousGram-negative bacterial clinical isolates. Against 100 strains of S.aureus, Example 5 (MIC₉₀ 0.25 μg/mL) was the most active compound testedand maintained this activity against isolates resistant to levofloxacin,linezolid and vancomycin. This high degree of antibacterial activity andlack of cross resistance was also observed against 99 strains ofcoagulase negative staphylococci including S. epidermidis (MIC₉₀ 0.25μg/mL, n=37), S. haemolyticus (MIC₉₀ 0.25 μg/mL, n=21), S. lugdunensis(MIC₉₀ 0.5 μg/mL, n=111), and S. saprophyticus (MIC₉₀ 0.5 μg/mL, n=16).Against 100 strains each of S. pneumoniae, S. pyogenes, and S.Agalactiae, Example 5 was very active with MIC₅₀ and MIC₉₀ values of0.125 μg/mL and 0.25 μg/mL, respectively. No cross resistance wasobserved for Example 5 to any of the streptococci resistant tolevofloxacin, erythromycin, or amoxicillin.

Compared to the staphylococci and streptococci, reduced activity wasobserved for Example 5 against enterococci with E. faecalis (n=51)resulting in the lowest MICs (MIC range 0.125-2 μg/mL and MIC₉₀ 2 μg/mL)and E. faecium MICs being approximately 8-fold higher (MIC₉₀ 16 μg/mL).Activity of Example 5 was measured against 11 strains each of Bacillussubtilis and B. cereus (as a surrogate for B. anthracis. MIC₉₀s againstboth species were 0.5 μg/mL. BSL3 testing of Example 5 against B.anthracis confirmed this activity (MIC range 0.125-1 μg/mL, and MIC₉₀0.5 μg/mL).

The antibacterial activity of Example 5 also encompassed fastidiousGram-negative organisms including Haemophilus influenzae (n=29),Legionella pneumophila (n=11), and 17 strains of Neisseria gonorrhoeae.MIC ranges versus these organism groups were 0.125-1 μg/mL, 0.008-0.06μg/mL and 0.03-0.25 μg/mL, respectively. Corresponding MIC₉₀s were 1μg/mL, 0.06 μg/mL and 0.125 μg/mL, respectively. No cross resistance toExample 5 was observed in strains of N. gonorrhoeae resistant tociprofloxacin.

Serum protein binding effects on MIC values for Example 5 were assessedin varying concentrations of both mouse and human serum (0, 10, 25, and50%). Against the 9 S. aureus strains tested, a 2- to 8-fold MICincrease was observed for Example 5 in the presence of 50% human serumand greater protein binding effects (8- to 32-fold MIC increases) wereobserved in 50% mouse serum.

Example 5 and comparators were evaluated for bactericidal activityagainst 7 S. aureus strains and 1 strain of Streptococcus pyogenes.Example 5, levofloxacin, and vancomycin were bactericidal against allthe strains tested with minimum bactericidal concentrations (MBCs)within 2-fold of the MIC. The bactericidal activity of Example 5 wasconfirmed by in vitro time-kill studies.

TABLE 12 In vitro antibacterial activity of Example 5 againstmiscellaneous bacterial isolates Example 5 Organism MIC μg/mLAcinetobacter baumannii (in vivo strain) 4 Acinetobacter baumannii(multi-drug resistant) 16 Acinetobacter baumannii 4 Burkholderia cepacia64 Candida albicans (ATCC 90028 CLSI QC Strain) >64 Citrobacter freundii16 Citrobacter koseri 64 Enterobacter aerogenes 64 Enterobacter cloacae32 Enterobacter cloacae (Chromosomal AmpC) 32 Enterococcus faecalis(ATCC 29212 CLSI QC Strain) 1 Enterococcus faecalis 2 Enterococcusfaecalis (Vancomycin-R, fluoroquinolone-R) 0.5 Enterococcus faecium 16Enterococcus faecium (Vancomycin-R, fluoroquinolone-R) 8 Escherichiacoli (ATCC 25922 CLSI QC Strain) 2 Escherichia coli (K12(W3110) 2Escherichia coli (TolC- of ATCC 25922) <0.06 Escherichia coli + 2% Humanalbumin (ATCC 25922) <0.06 Escherichia coli (ATCC 35218 CLSI QC Strain)4 Haemophilus influenzae (ATCC 49619 CLSI QC Strain) 0.25 Klebsiellaoxytoca 32 Klebsiella pneumoniae (ATCC 700603 CLSI QC Strain) >64Klebsiella pneumoniae 64 Klebsiella pneumoniae (In vivo strain) 16Klebsiella pneumoniae 64 Moraxella catarrhalis (ATCC 43617) 0.125Proteus mirabilis 8 Proteus vulgaris 32 Pseudomonas aeruginosa(PAO1) >64 Pseudomonas aeruginosa (PAO1, mexABCDXY-) 2 Pseudomonasaeruginosa (clinical isolate) >64 Serratia marcescens >64 Staphylococcusaureus (ATCC 29213, CLSI QC Strain) 0.125 Staphylococcus aureus + 2%Human albumin 0.25 (ATCC 29213, CLSI QC Strain) Staphylococcus aureus(MSSA, in vivo strain) 0.125 Staphylococcus aureus (MRSA,fluoroquinolone-R) 0.25 Staphylococcus aureus (MRSA) 0.5 Staphylococcusaureus (In vivo Strain) 0.25 Staphylococcus aureus (Mu3, VISA) 0.25Staphylococcus aureus (MRSA, USA100) 0.125 Staphylococcus epidermidis(MRSE) 0.25 Staphylococcus haemolyticus 0.25 Staphylococcus lugdunensis1 Staphylococcus saprophyticus 0.5 Streptococcus agalactiae 0.5Streptococcus constellatus 0.03 Streptococcus pyogenes 0.125Streptococcus pyogenes 0.25 Streptococcus pneumonia (ATCC 49619, CLSI QCStrain) 0.25 Streptococcus pneumonia (In vivo Strain) 0.25 Streptococcuspneumonia (Penicillin, -erythromycin- and 0.25fluoroquinolone-resistant) Stenotrophomonas maltophilia >64

TABLE 13 In vitro antibacterial activity of Example 5 against anaerobicbacterial species Example 5 Organism MIC μg/mL Clostridium difficile(ATCC 70057, CLSI QC Strain) 0.125 Clostridium difficile 0.125Clostridium perfringens 0.5 Propionibacterium acnes 2 Finegoldia magna(ATCC 53516) <0.03 Bacteroides thetaiotaomicron 8 Bacteroidesthetaiotaomicron (ATCC 29741, CLSI 8 QC Strain) Prevotellamelaninogenica 0.25 Bacteroides fragilis (ATCC 25285, CLSI QC Strain) 2Bacteroides fragilis 4 Bacteroides fragilis 4 Bacteroides fragilis 4Bacteroides fragilis 8

Summary

Example 5 is DNA gyrase/topoisomerase inhibitor with in vitroantibacterial activity against key Gram-positive (S. aureus, S.epidermidis, S. haemolyticus, Streptococcus pneumoniae, S. pyogenes, andS. agalactiae), fastidious Gram-negative (Haemophilus influenzae,Legionella pneumophila, Moraxella catarrhalis, Neisseria gonorrhoeae),and anaerobic (Clostridium difficile) bacterial species includingisolates with known resistance to fluoroquinolones. No cross resistancewas observed for Example 5 against recent bacterial clinical isolateswith resistance to other drug classes, including macrolides, β-lactams,glycopeptides, and oxazolidinones.

Emergence of Resistance in Staphylococcus aureus and Streptococcuspyogenes with Serial Passage

The goal of this study was to determine the emergence of resistance toExample 5 during serial passage in a representative isolate ofmethicillin-sensitive Staphylococcus aureus, methicillin-resistant S.aureus and Streptococcus pyogenes.

Freshly grown S. aureus 516 and 2398 as well as S. pyogenes 838 wereharvested from blood agar plates (Remel, Lenexa Kans.), suspended in 3mL cation-adjusted Mueller Hinton 2 broth (MHB2)(Sigma-Aldrich, St.Louis Mo.) and a sample frozen as passage zero. These cultures werediluted to a 0.5 McFarland in sterile saline (Remel) which was thendiluted 1:200 into fresh broth and used as the inoculum. The media andincubation conditions used throughout the experiment were MHB2 and 36°C. in ambient air for S. aureus and MHB2 with the addition of 2.5% lysedhorse blood and 36° C. in 5% CO₂ (Hema Resource Inc., Aurora, Oreg.) forS. pyogenes 838.

A series of two-fold increasing concentrations of Example 5 were made inDMSO and 40 μL of each concentration dispensed into wells of a 24-wellculture plates (Costar, Corning N.Y.). Plates were sealed and frozen at−80° C. and thawed every day. A total of 2 mL of the inculum was addedto each well and the plates were for 20 to 24 hours. Bacterial cellsfrom the well containing the highest concentration of test compound thatpermitted visible bacterial growth were frozen in 20% glycerol andstored at −70° C. and were also back-diluted to a 0.5 McFarland insterile saline (Remel) and subsequently diluted into fresh media. Thisdiluted culture, representing cells from 0.5×MIC, was then dispensedinto a fresh 24-well culture plate containing the series of increasingconcentrations of test compound. This was repeated for twenty days.

The frozen samples were then single colony purified on blood agar platesin the absence of compound and tested for susceptibility using astandard broth microdilution assay, performed in accordance withdocument M07-A8 of the Clinical Laboratory Standards Institute (Methodsfor dilution antimicroia susceptibility tests for bacteria that growaerobically; approved standard. Eighth edition. Wayne, Pa. Volume 29.No. 2. 2009). Isolates from several passages with an elevated MIC valueagainst Example 5 representing a decrease in susceptibility wereselected for investigation by sequence analysis. Whole genomic DNA wasprepared from selected isolates using a standard Genomic DNA preparationkit (Promega, Madison Wis.). The genes encoding both subunits of DNAgyrase (gyrA and gyrB) and Topoisomerase IV (parC and parE) wereamplified using a High Fidelity PCR mix (Roche, Nutley, N.J.). Thepolymerase chain reaction (PCR) product was purified using a QIAquickPCR Purification kit (Qiagen, Valencia, Calif.) and sequenced in anApplied Biosystems 3100 Genetic Analyzer (ABI, Foster City, Calif.)using the appropriate primers for S. aureus and S. pneumoniae. Ifchanges were observed, a second independent PCR product was amplifiedand sequenced to confirm the variation was genuine and not as a resultof an incorporation error during PCR amplification.

Growth of S. aureus and S. pyogenes over twenty passages in liquidmedium containing sub-inhibitory concentrations of Example 5 was done tostudy the emergence of resistance. After twenty passages in the presenceof increasing selective pressure of Example 5, variants of S. aureus andS. pyogenes ARC838 had been isolated that displayed 32-fold, 16-fold,and 8-fold decreases in susceptibility over the starting culture. Thisloss of susceptibility to Example 5 did not correlate with any changesin susceptibility that was greater than 4-fold to linezolid, vancomycin,and levofloxacin.

In Vitro Activity and Potency of Example 5 Tested Against Neisseriagonorrhoeae

Neisseria gonorrhoeae is a significant cause of worldwide sexuallytransmitted disease. Penicillin historically was effective in thetreatment of gonorrhea but plasmid-mediated penicillinase producing N.gonorrhoeae (PPNG) strains have spread worldwide limiting the empiricuse of penicillin to certain geographical regions with a knownlow-prevalence of PPNG, other penicillin resistance mechanisms.Additionally, resistance development has occurred for several of thealternative antimicrobial class agents used for empiric therapy ofgonococcal infections, including fluoroquinolones (ciprofloxacin),tetracyclines and macrolides (azithromycin). A collection of 100Neisseria gonorrhoeae, including isolates which were non-susceptible toazithromycin, ciprofloxacin, penicillin, and tetracycline, were testedin vitro by the CLSI reference agar dilution method against Example 5and comparator agents. The results indicated that Example 5 was highlyactive against all isolates tested (MIC values at ≦0.25 μg/ml) and thereappeared to be no cross-resistance with other tested comparator classes.

A total of 100 stock clinical and ATCC quality control N. gonorrhoeaeisolates from the collection at JMI Laboratories (North Liberty, IowaUSA) were tested. Collection included strains with the followingcharacteristics:

Phenotype No. of Isolates Ciprofloxacin-resistant  47^(a)Penicillin-resistant  63^(b) Ciprofloxacin R & Penicillin R  24^(c)Total 100^(d) ^(a)Mostly North American and a few European isolates^(b)Approximately equal numbers of North American and Europe isolates^(c)Mostly North American and a few European isolates ^(d)Twenty-sevenisolates with azithromycin MIC at ≧0.5 μg/mL (non-susceptible)

Methods:

A. MIC values for N. gonorrhoeae were determined using the referenceCLSI agar dilution method for gonococci as described in M07-A9 [2012].B. Agar dilution plates (GC agar base with 1% defined supplement) for N.gonorrhoeae testing were produced by JMI Laboratories.C. Comparator agents were provided by JMI Laboratories throughSigma-Aldrich or their respective manufacturer.D. Quality control (QC) ranges and interpretive criteria for thecomparator compounds were as published in CLSI M100-S23 [2013] andEUCAST [2013]. The QC strain was N. gonorrhoeae ATCC 49226.

Example 5 was active against all N. gonorrhoeae strains testedexhibiting a MIC range of ≦0.004 to 0.25 μg/mL and a MIC_(50/90) at0.06/0.125 μg/mL. A total of 99.0% of isolates exhibited MICvalues≦0.125 μg/mL. There was only one isolate with a MIC value at 0.25μg/mL.

Example 5 demonstrated similar activity against penicillin-intermediateand -resistant strains with a modal MIC value at 0.06 μg/mL andMIC_(50/90) values of 0.06/0.06 μg/mL and 0.06/0.12 μg/mL [85.7% ofisolates at ≦0.06 μg/mL], respectively.

The ciprofloxacin-intermediate and -resistant strains also showed amodal MIC value to Example 5 at 0.06 μg/mL with MIC_(50/90) values of0.06/0.12 μg/mL.

Example 5 exhibited similar activity against tetracycline-intermediateand -resistant strains with a modal MIC value at 0.06 μg/mL andMIC_(50/90) values of 0.06/0.06 μg/mL and 0.06/0/0.12 μg/mL [66.7% ofisolates at ≦0.06 μg/mL], respectively.

The modal values for the azithromycin-susceptible and -intermediateisolates were 0.06 μg/mL with MIC_(50/90) values of 0.06/0.06 μg/mL and0.06/0/0.12 μg/mL [66.7% of isolates at ≦0.06 μg/mL], respectively.

The MIC_(50/90) values against all 100 isolates for azithromycin were0.25/0.5 μg/mL; for cefixime, 0.03/0.06 μg/mL; for ceftriaxone0.015/0.06 μg/mL; for ciprofloxacin, 0.25/>2 μg/mL; for penicillin 2/>2μg/mL; and for tetracycline 1/2 μg/mL.

Example 5 (MIC₉₀, 0.12 μg/mL) was four-fold more active thanazithromycin (MIC₉₀, 0.5 μg/mL), two-fold less active than cefixime andceftriazone (MIC₉₀ 0.06 μg/mL), 16-fold more active than tetracycline(MIC₉₀, 2 μg/mL) and >32-fold more active than ciprofloxacin andpenicillin (MIC₉₀. 2 μg/mL).

Example 5 MIC values when tested against the QC strain (N. gonorrhoeaeATCC 49226) were 0.06, 0.12 and 0.12 μg/mL.

Summary:

Example 5 was highly active against N. gonorrhoeae isolates with 99.0%of isolates exhibiting MIC values≦0.125 μg/mL. Example 5 was two-foldless active that cefixime and ceftriaxone and ranged from 4->32-foldmore active than azithromycin, ciprofloxacin, penicillin andtetracycline. The modal MIC value for Example 5 remained the same (0.06μg/mL) for various subsets of isolates including those that werenon-susceptible to comparator agents. MIC₉₀ values for susceptiblephenotypes (ciprofloxacin-susceptible, tetracycline-susceptible andazithromycin-susceptible) were at 0.06 μg/mL. For non-susceptiblephenotypes, MIC₉₀ values were at 0.06-0.12 μg/mL indicating the highlevel of activity and the lack of significant cross-resistance ofExample 5 with comparator agents.

1. A compound, or a pharmaceutically acceptable salt thereof, whereinthe compound has the structure of formula (I):

wherein X is fluorine or chlorine; R¹ is selected from the groupconsisting of hydrogen, phenyl, —C≡N, tetrahydropyranyl,N-methyl-1,2,4-triazolyl, pyrimidinyl, pyridinyl, pyrazinyl,cyclopropyl, —C≡CH, —CH═CH₂, and C₁-C₃ alkyl, which C₁-C₃ alkyl isoptionally substituted with one or more of: —OR¹⁰, halogen, —C≡N, —N₃,—SO₂CH₃, —SCH₃, —CH═CH₂, —CH═NOR¹¹ and phenyl; R² is selected from thegroup consisting of hydrogen, —C≡N, pyridinyl, C₁-C₃ alkyl, which C₁-C₃alkyl is optionally substituted with one or more of: halogen, —OR²⁰ and—CH═NOR²¹; R³ is hydrogen or C₁-C₃ alkyl; R¹⁰ is for each occurrenceindependently selected from the group consisting of hydrogen, C₁-C₄alkyl and —(CH₂)₂OCH₃; and R¹¹, R²⁰ and R²¹ are for each occurrenceindependently hydrogen or C₁-C₄ alkyl.
 2. The compound, orpharmaceutically acceptable salt thereof, of claim 1, wherein R¹⁰ ishydrogen, methyl, ethyl or —(CH₂)₂OCH₃.
 3. The compound, orpharmaceutically acceptable salt thereof, of claim 1, wherein R¹¹ ishydrogen or methyl.
 4. The compound, or pharmaceutically acceptable saltthereof, of claim 1, wherein R²⁰ is hydrogen, methyl or ethyl.
 5. Thecompound, or pharmaceutically acceptable salt thereof, of claim 1,wherein R²¹ is hydrogen or methyl.
 6. The compound, or pharmaceuticallyacceptable salt thereof, of claim 1 wherein R¹ is selected from thegroup consisting of hydrogen, methyl, ethyl, phenyl, —CH₂-phenyl, —CH₂F,—CH₂OCH₃, —CH₂CH═CH₂, tetrahydropyranyl, —(CH₂)₃OH, —(CH₂)₃F, —(CH₂)₃OH,—(CH₂)₃F, —CH═CH₂, —C≡N, —CH═NOCH₃, —CH₂SCH₃, —CH₂SO₂CH₃, —CH₂N₃,—CH₂OCH₂CH₃, —CH₂O(CH₂)₂OCH₃, cyclopropyl, pyridinyl, —CH(CH₃)OCH₃,pyrimidinyl, pyrazinyl, —C≡CH, N-methyl-1,2,4-triazolyl, —CH(OH)CH₃,—CH═NOH and —CH₂OH.
 7. The compound, or pharmaceutically acceptable saltthereof, of claim 1, wherein R² is selected from the group consisting ofhydrogen, methyl, ethyl, —CH₂F, —CH₂OCH₃, —CH₂OH, —CH═NOH, —CH₂N₃,pyridinyl, —C≡N and —CH═NHOCH₃.
 8. The compound, or pharmaceuticallyacceptable salt thereof, of claim 1, wherein R³ is hydrogen or methyl.9. The compound, or pharmaceutically acceptable salt thereof, of claim1, wherein the compound is selected from the group consisting of:(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-(2-oxo-1,3-oxazolidin-3-yl)-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5S)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5R)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-[(4S)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-[(4R)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione);(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-[(4R)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-[(4S)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-(5,5-Dimethyl-2-oxo-1,3-oxazolidin-3-yl)-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-[(5S)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-[(5R)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Chloro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Chloro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;((2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((R)-5-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((4S,5R)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-1-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((4R,5S)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-1-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((S)-4-Allyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((S)-5-(hydroxymethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;((2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-[(4S-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-hydroxypropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((S)-4-(2-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Chloro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Choro-8-((S)-4-(3-hydroxpropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Choro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(hydroxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-2-oxo-4-vinyloxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-4-carbonitrile;(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-[(5R)-5-(Azidomethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylthio)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylsulfonyl)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((R)-4-(Azidomethyl)-2-oxooxazolidin-3-yl)-1-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((S)-4-(azidomethyl)-2-oxooxazolidin-3-yl)-1-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-[(4S)-4-(Ethoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(2-methoxyethoxy)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-8-((R)-4-(Difluoromethyl)-2-oxooxazolidin-3-yl)-1-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((S)-4-Cyclopropyl-2-oxooxazolidin-3-yl)-1-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((R)-4-((R)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((S)-4-Ethynyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((S)-4-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;{(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidin-4-yl}acetonitrile;(2R,4S,4aS)-8((R)-4-((R)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-8-((R)-4-((S)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;(2R,4S,4aS)-11-fluoro-8-{(4S)-4-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;(5R)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrile;and(5S)-3-[(2R,4S,4aS)-11-fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrile,or a pharmaceutically acceptable salt thereof.
 10. A pharmaceuticalcomposition comprising a compound of claim 1, or a pharmaceuticallyacceptable salt thereof, and a pharmaceutically acceptable excipient ordiluent.
 11. (canceled)
 12. (canceled)
 13. A method for treating abacterial infection in a subject in need thereof comprisingadministering an effective amount of a compound of formula (I) asclaimed in claim 1, or a pharmaceutically acceptable salt thereof.
 14. Amethod for inhibiting bacterial DNA gyrase, comprising administering aneffective amount of a compound of formula (I) as claimed in claim 1, ora pharmaceutically acceptable salt thereof.